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  • richardmitnick 1:06 pm on October 16, 2021 Permalink | Reply
    Tags: "Ultrafast magnetism- heating magnets and freezing time", , , Demagnetization, HAMR: Heat Assisted Magnetic Recording, , , , , Spintronics   

    From Helmholtz Center for Materials and Energy [Helmholtz-Zentrum Berlin für Materialien und Energie] (DE): “Ultrafast magnetism- heating magnets and freezing time” 

    From Helmholtz Center for Materials and Energy [Helmholtz-Zentrum Berlin für Materialien und Energie] (DE)

    15.10.2021

    Dr. Régis Decker
    Tel (030) 8062 – 14641
    Fax (030) 8062-14987
    regis.decker@helmholtz-berlin.de

    Press officer:
    Dr. Antonia Rötger
    Dr. Antonia Rötger
    Tel (030) 8062 – 43733
    Fax (030) 8062 – 42998
    antonia.roetger@helmholtz-berlin.de

    Magnetic solids can be demagnetized quickly with a short laser pulse, and there are already so-called HAMR (Heat Assisted Magnetic Recording) memories on the market that function according to this principle. However, the microscopic mechanisms of ultrafast demagnetization remain unclear. Now, a team at HZB has developed a new method at BESSY II to quantify one of these mechanisms and applied it to the rare-earth element Gadolinium, whose magnetic properties are caused by electrons on both the 4f and the 5d shells. This study is completing a series of experiments done by the team on Nickel, Iron-Nickel Alloys. Understanding these mechanisms is useful for developing ultrafast data storage devices.

    1
    The picture shows the glowing filament which keeps the sample at constant temperatures during the measurements. © HZB.

    New materials should make information processing more efficient, for example, through ultrafast spintronic devices that store data with less energy input. But to date, the microscopic mechanisms of ultrafast demagnetization are not fully understood. Typically, the process of demagnetization is studied by sending an ultrashort laser pulse to the sample, thereby heating it up, and then analyzing how the system evolves in the first picoseconds afterward.

    Snapshot of the lattice condition

    “Our approach is different,” explains Dr. Régis Decker, lead author of the study. “We keep the sample at a certain temperature during the spectra acquisition. And we do that for many temperatures, from -120°C to 450°C for Gd – and much higher (1000°C) for previous experiments with Ni and FeNi. This allows us to quantify the effect of the phonons for each temperature on the ultrafast demagnetization, where the temperatures of the lattice, electrons and spins subsystems evolve with time. In other words, by placing the system at a certain temperature, we do a capture of the lattice condition at a given time after the ultrashort laser pulse and we measure there.”

    Gadolinium examined

    The element gadolinium has 4f and 5d electron orbitals, which both contribute to its ferromagnetic properties. The higher the temperature, the more the crystalline sample vibrates – and as physicists say: the more the population of phonons increases, and the more likely spin-flips are to occur due to the scattering of electrons with phonons from the crystal lattice.

    Scattering rates distinguished

    Using the method of inelastic X-ray scattering (RIXS), the physicists were not only able to determine the number of phonons at a given temperature, but also to distinguish the interactions between phonons and 4f- and 5d-electrons. Using the strict X-ray spectroscopic symmetry selection rules, the evaluation succeeded in distinguishing between the scattering rates of the 4f and 5d electrons.

    5d electrons interact with phonons

    The data show that there is hardly any scattering between the localized 4f electrons and phonons, but most of the scattering process takes place between 5d electrons and phonons, so that a spin-flip only occurs there. “Our approach evidences that the electron-phonon scattering, which is known to be one of the main trigger of ultrafast demagnetization, applies to the 5d electrons only. Interestingly, it also shows the presence of a temperature threshold, which depends on the material, below which this mechanism does not occur. This indicates the existence of another microscopic mechanism at lower temperature, as predicted by theory”, Decker explains.

    Note:

    This study is completing a series of experiments done by the HZB team at BESSY II on Nickel, Iron-Nickel Alloys and now Gadolinium.

    Science papers:

    New publication on Gadolinium: Applied Physics Letters

    On Nickel: Scientific Reports

    On Iron-Nickel-Alloy: Scientific Reports

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Helmholtz-Zentrum Berlin für Materialien und Energie (Helmholtz Center for Materials and Energy, HZB) is part of the Helmholtz Association of German Research Centres [Helmholtz-Gemeinschaft Deutscher Forschungszentren] (DE). The institute studies the structure and dynamics of materials and investigates solar cell technology. It also runs the third-generation BESSY II synchrotron in Adlershof. Until the end of 2019 it ran the 10 megawatt BER II nuclear research reactor at the Lise Meitner campus in Wannsee.

    The Helmholtz-Zentrum Berlin was created on 1 January 2009 by the merger of Hahn-Meitner-Institut Berlin (HMI) and Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY), thus bringing BESSY into the Helmholtz Association.[4]

    The Hahn-Meitner-Institut Berlin (HMI), named after Otto Hahn and Lise Meitner, was founded 14 March 1959 in Berlin-Wannsee to operate the BER I research reactor that began operation with 50 kW on 24 July 1958. Research originally focused on radiochemistry. In 1971, the federal government took over a 90% share in the HMI.

    The Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY) was founded in 1979. The first synchrotron BESSY I in Berlin-Wilmersdorf began operations in 1982.

     
  • richardmitnick 10:42 am on September 4, 2021 Permalink | Reply
    Tags: "Rice physicists find ‘magnon’ origins in 2D magnet", , , In van der Waals materials atomically thin 2D layers are stacked like pages in a book., , , Spintronics   

    From Rice University (US) : “Rice physicists find ‘magnon’ origins in 2D magnet” 

    From Rice University (US)

    September 1, 2021
    Jade Boyd

    Topological feature could prove useful for encoding information in electron spins.

    1
    Graduate student Lebing Chen displays chromium triiodide crystals he made in a Rice University laboratory. Stacked layers of atomically thin 2D chromium triiodide have unusual electronic and magnetic properties that could prove useful for “spintronic” technologies that encode information in the spins of electrons. (Photo by Jeff Fitlow/Rice University.)

    Rice physicists have confirmed the topological origins of magnons, magnetic features they discovered three years ago in a 2D material that could prove useful for encoding information in the spins of electrons.

    The discovery, described in a study published online this week in the American Physical Society (US) journal Physical Review X, provides a new understanding of topology-driven spin excitations in materials known as in 2D van der Waals magnets. The materials are of growing interest for spintronics, a movement in the solid-state electronics community toward technologies that use electron spins to encode information for computation, storage and communications.

    Spin is an intrinsic feature of quantum objects and the spins of electrons play a key role in bringing about magnetism.

    Rice physicist Pengcheng Dai, co-corresponding author of the PRX study, said inelastic neutron-scattering experiments on the 2D material chromium triiodine confirmed the origin of the topological nature of spin excitations, called magnons, that his group and others discovered in the material in 2018.

    The group’s latest experiments at DOE’s Oak Ridge National Laboratory’s (US) Spallation Neutron Source showed “spin-orbit coupling induces asymmetric interactions between spins” of electrons in chromium triiodine, Dai said. “As a result, the electron spins feel the magnetic field of moving nuclei differently, and this affects their topological excitations.”

    In van der Waals materials atomically thin 2D layers are stacked like pages in a book. The atoms within layers are tightly bonded, but the bonds between layers are weak. The materials are useful for exploring unusual electronic and magnetic behaviors. For example, a single 2D sheet of chromium triiodine has the same sort of magnetic order that makes magnetic decals stick to a metal refrigerator. Stacks of three or more 2D layers also have that magnetic order, which physics call ferromagnetic. But two stacked sheets of chromium triiodine have an opposite order called antiferromagnetic.

    That strange behavior led Dai and colleagues to study the material. Rice graduate student Lebing Chen, the lead author of this week’s PRX study and of the 2018 study in the same journal[Physical Review X], developed methods for making and aligning sheets of chromium triiodide for experiments at ORNL. By bombarding these samples with neutrons and measuring the resulting spin excitations with neutron time-of-flight spectrometry, Chen, Dai and colleagues can discern unknown features and behaviors of the material.

    In their previous study, the researchers showed chromium triiodine makes its own magnetic field thanks to magnons that move so fast they feel as if they are moving without resistance. Dai said the latest study explains why a stack of two 2D layers of chromium triiodide has antiferromagnetic order.

    “We found evidence of a stacking-dependent magnetic order in the material,” Dai said. Discovering the origins and key features of the state is important because it could exist in other 2D van der Waals magnets.

    Additional co-authors include Bin Gao of Rice, Jae-Ho Chung of Korea University, Matthew Stone, Alexander Kolesnikov, Barry Winn, Ovidiu Garlea and Douglas Abernathy of ORNL, and Mathias Augustin and Elton Santos of the University of Edinburgh.

    The research was funded by the National Science Foundation, the Welch Foundation, the National Research Foundation of Korea, the United Kingdom’s Engineering and Physical Research Council and the University of Edinburgh and made use of facilities provided by the United Kingdom’s ARCHER National Supercomputing Service and the Department of Energy’s Office of Science.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings


    Stem Education Coalition

    Rice University (US) [formally William Marsh Rice University] is a private research university in Houston, Texas. It is situated on a 300-acre campus near the Houston Museum District and is adjacent to the Texas Medical Center.

    Opened in 1912 after the murder of its namesake William Marsh Rice, Rice is a research university with an undergraduate focus. Its emphasis on education is demonstrated by a small student body and 6:1 student-faculty ratio. The university has a very high level of research activity. Rice is noted for its applied science programs in the fields of artificial heart research, structural chemical analysis, signal processing, space science, and nanotechnology. Rice has been a member of the Association of American Universities (US) since 1985 and is classified among “R1: Doctoral Universities – Very high research activity”.

    The university is organized into eleven residential colleges and eight schools of academic study, including the Wiess School of Natural Sciences, the George R. Brown School of Engineering, the School of Social Sciences, School of Architecture, Shepherd School of Music and the School of Humanities. Rice’s undergraduate program offers more than fifty majors and two dozen minors, and allows a high level of flexibility in pursuing multiple degree programs. Additional graduate programs are offered through the Jesse H. Jones Graduate School of Business and the Susanne M. Glasscock School of Continuing Studies. Rice students are bound by the strict Honor Code, which is enforced by a student-run Honor Council.

    Rice competes in 14 NCAA Division I varsity sports and is a part of Conference USA, often competing with its cross-town rival the University of Houston. Intramural and club sports are offered in a wide variety of activities such as jiu jitsu, water polo, and crew.

    The university’s alumni include more than two dozen Marshall Scholars and a dozen Rhodes Scholars. Given the university’s close links to National Aeronautics Space Agency (US), it has produced a significant number of astronauts and space scientists. In business, Rice graduates include CEOs and founders of Fortune 500 companies; in politics, alumni include congressmen, cabinet secretaries, judges, and mayors. Two alumni have won the Nobel Prize.

    Background

    Rice University’s history began with the demise of Massachusetts businessman William Marsh Rice, who had made his fortune in real estate, railroad development and cotton trading in the state of Texas. In 1891, Rice decided to charter a free-tuition educational institute in Houston, bearing his name, to be created upon his death, earmarking most of his estate towards funding the project. Rice’s will specified the institution was to be “a competitive institution of the highest grade” and that only white students would be permitted to attend. On the morning of September 23, 1900, Rice, age 84, was found dead by his valet, Charles F. Jones, and was presumed to have died in his sleep. Shortly thereafter, a large check made out to Rice’s New York City lawyer, signed by the late Rice, aroused the suspicion of a bank teller, due to the misspelling of the recipient’s name. The lawyer, Albert T. Patrick, then announced that Rice had changed his will to leave the bulk of his fortune to Patrick, rather than to the creation of Rice’s educational institute. A subsequent investigation led by the District Attorney of New York resulted in the arrests of Patrick and of Rice’s butler and valet Charles F. Jones, who had been persuaded to administer chloroform to Rice while he slept. Rice’s friend and personal lawyer in Houston, Captain James A. Baker, aided in the discovery of what turned out to be a fake will with a forged signature. Jones was not prosecuted since he cooperated with the district attorney, and testified against Patrick. Patrick was found guilty of conspiring to steal Rice’s fortune and he was convicted of murder in 1901 (he was pardoned in 1912 due to conflicting medical testimony). Baker helped Rice’s estate direct the fortune, worth $4.6 million in 1904 ($131 million today), towards the founding of what was to be called the Rice Institute, later to become Rice University. The board took control of the assets on April 29 of that year.

    In 1907, the Board of Trustees selected the head of the Department of Mathematics and Astronomy at Princeton University, Edgar Odell Lovett, to head the Institute, which was still in the planning stages. He came recommended by Princeton University (US)‘s president, Woodrow Wilson. In 1908, Lovett accepted the challenge, and was formally inaugurated as the Institute’s first president on October 12, 1912. Lovett undertook extensive research before formalizing plans for the new Institute, including visits to 78 institutions of higher learning across the world on a long tour between 1908 and 1909. Lovett was impressed by such things as the aesthetic beauty of the uniformity of the architecture at the University of Pennsylvania, a theme which was adopted by the Institute, as well as the residential college system at Cambridge University in England, which was added to the Institute several decades later. Lovett called for the establishment of a university “of the highest grade,” “an institution of liberal and technical learning” devoted “quite as much to investigation as to instruction.” [We must] “keep the standards up and the numbers down,” declared Lovett. “The most distinguished teachers must take their part in undergraduate teaching, and their spirit should dominate it all.”

    Establishment and growth

    In 1911, the cornerstone was laid for the Institute’s first building, the Administration Building, now known as Lovett Hall in honor of the founding president. On September 23, 1912, the 12th anniversary of William Marsh Rice’s murder, the William Marsh Rice Institute for the Advancement of Letters, Science, and Art began course work with 59 enrolled students, who were known as the “59 immortals,” and about a dozen faculty. After 18 additional students joined later, Rice’s initial class numbered 77, 48 male and 29 female. Unusual for the time, Rice accepted coeducational admissions from its beginning, but on-campus housing would not become co-ed until 1957.

    Three weeks after opening, a spectacular international academic festival was held, bringing Rice to the attention of the entire academic world.

    Per William Marsh Rice’s will and Rice Institute’s initial charter, the students paid no tuition. Classes were difficult, however, and about half of Rice’s students had failed after the first 1912 term. At its first commencement ceremony, held on June 12, 1916, Rice awarded 35 bachelor’s degrees and one master’s degree. That year, the student body also voted to adopt the Honor System, which still exists today. Rice’s first doctorate was conferred in 1918 on mathematician Hubert Evelyn Bray.

    The Founder’s Memorial Statue, a bronze statue of a seated William Marsh Rice, holding the original plans for the campus, was dedicated in 1930, and installed in the central academic quad, facing Lovett Hall. The statue was crafted by John Angel. In 2020, Rice students petitioned the university to take down the statue due to the founder’s history as slave owner.

    During World War II, Rice Institute was one of 131 colleges and universities nationally that took part in the V-12 Navy College Training Program, which offered students a path to a Navy commission.

    The residential college system proposed by President Lovett was adopted in 1958, with the East Hall residence becoming Baker College, South Hall residence becoming Will Rice College, West Hall becoming Hanszen College, and the temporary Wiess Hall becoming Wiess College.

    In 1959, the Rice Institute Computer went online. 1960 saw Rice Institute formally renamed William Marsh Rice University. Rice acted as a temporary intermediary in the transfer of land between Humble Oil and Refining Company and NASA, for the creation of NASA’s Manned Spacecraft Center (now called Johnson Space Center) in 1962. President John F. Kennedy then made a speech at Rice Stadium reiterating that the United States intended to reach the moon before the end of the decade of the 1960s, and “to become the world’s leading space-faring nation”. The relationship of NASA with Rice University and the city of Houston has remained strong to the present day.

    The original charter of Rice Institute dictated that the university admit and educate, tuition-free, “the white inhabitants of Houston, and the state of Texas”. In 1963, the governing board of Rice University filed a lawsuit to allow the university to modify its charter to admit students of all races and to charge tuition. Ph.D. student Raymond Johnson became the first black Rice student when he was admitted that year. In 1964, Rice officially amended the university charter to desegregate its graduate and undergraduate divisions. The Trustees of Rice University prevailed in a lawsuit to void the racial language in the trust in 1966. Rice began charging tuition for the first time in 1965. In the same year, Rice launched a $33 million ($268 million) development campaign. $43 million ($283 million) was raised by its conclusion in 1970. In 1974, two new schools were founded at Rice, the Jesse H. Jones Graduate School of Management and the Shepherd School of Music. The Brown Foundation Challenge, a fund-raising program designed to encourage annual gifts, was launched in 1976 and ended in 1996 having raised $185 million. The Rice School of Social Sciences was founded in 1979.

    On-campus housing was exclusively for men for the first forty years, until 1957. Jones College was the first women’s residence on the Rice campus, followed by Brown College. According to legend, the women’s colleges were purposefully situated at the opposite end of campus from the existing men’s colleges as a way of preserving campus propriety, which was greatly valued by Edgar Odell Lovett, who did not even allow benches to be installed on campus, fearing that they “might lead to co-fraternization of the sexes”. The path linking the north colleges to the center of campus was given the tongue-in-cheek name of “Virgin’s Walk”. Individual colleges became coeducational between 1973 and 1987, with the single-sex floors of colleges that had them becoming co-ed by 2006. By then, several new residential colleges had been built on campus to handle the university’s growth, including Lovett College, Sid Richardson College, and Martel College.

    Late twentieth and early twenty-first century

    The Economic Summit of Industrialized Nations was held at Rice in 1990. Three years later, in 1993, the James A. Baker III Institute for Public Policy was created. In 1997, the Edythe Bates Old Grand Organ and Recital Hall and the Center for Nanoscale Science and Technology, renamed in 2005 for the late Nobel Prize winner and Rice professor Richard E. Smalley, were dedicated at Rice. In 1999, the Center for Biological and Environmental Nanotechnology was created. The Rice Owls baseball team was ranked #1 in the nation for the first time in that year (1999), holding the top spot for eight weeks.

    In 2003, the Owls won their first national championship in baseball, which was the first for the university in any team sport, beating Southwest Missouri State (US) in the opening game and then the University of Texas and Stanford University twice each en route to the title. In 2008, President David Leebron issued a ten-point plan titled “Vision for the Second Century” outlining plans to increase research funding, strengthen existing programs, and increase collaboration. The plan has brought about another wave of campus constructions, including the erection the newly renamed BioScience Research Collaborative building (intended to foster collaboration with the adjacent Texas Medical Center), a new recreational center and the renovated Autry Court basketball stadium, and the addition of two new residential colleges, Duncan College and McMurtry College.

    Beginning in late 2008, the university considered a merger with Baylor College of Medicine, though the merger was ultimately rejected in 2010. Rice undergraduates are currently guaranteed admission to Baylor College of Medicine upon graduation as part of the Rice/Baylor Medical Scholars program. According to History Professor John Boles’ recent book University Builder: Edgar Odell Lovett and the Founding of the Rice Institute, the first president’s original vision for the university included hopes for future medical and law schools.

    In 2018, the university added an online MBA program, MBA@Rice.

    In June 2019, the university’s president announced plans for a task force on Rice’s “past in relation to slave history and racial injustice”, stating that “Rice has some historical connections to that terrible part of American history and the segregation and racial disparities that resulted directly from it”.

    Campus

    Rice’s campus is a heavily wooded 285-acre (115-hectare) tract of land in the museum district of Houston, located close to the city of West University Place.

    Five streets demarcate the campus: Greenbriar Street, Rice Boulevard, Sunset Boulevard, Main Street, and University Boulevard. For most of its history, all of Rice’s buildings have been contained within this “outer loop”. In recent years, new facilities have been built close to campus, but the bulk of administrative, academic, and residential buildings are still located within the original pentagonal plot of land. The new Collaborative Research Center, all graduate student housing, the Greenbriar building, and the Wiess President’s House are located off-campus.

    Rice prides itself on the amount of green space available on campus; there are only about 50 buildings spread between the main entrance at its easternmost corner, and the parking lots and Rice Stadium at the West end. The Lynn R. Lowrey Arboretum, consisting of more than 4000 trees and shrubs (giving birth to the legend that Rice has a tree for every student), is spread throughout the campus.

    The university’s first president, Edgar Odell Lovett, intended for the campus to have a uniform architecture style to improve its aesthetic appeal. To that end, nearly every building on campus is noticeably Byzantine in style, with sand and pink-colored bricks, large archways and columns being a common theme among many campus buildings. Noteworthy exceptions include the glass-walled Brochstein Pavilion, Lovett College with its Brutalist-style concrete gratings, Moody Center for the Arts with its contemporary design, and the eclectic-Mediterranean Duncan Hall. In September 2011, Travel+Leisure listed Rice’s campus as one of the most beautiful in the United States.

    Lovett Hall, named for Rice’s first president, is the university’s most iconic campus building. Through its Sallyport arch, new students symbolically enter the university during matriculation and depart as graduates at commencement. Duncan Hall, Rice’s computational engineering building, was designed to encourage collaboration between the four different departments situated there. The building’s foyer, drawn from many world cultures, was designed by the architect to symbolically express this collaborative purpose.

    The campus is organized in a number of quadrangles. The Academic Quad, anchored by a statue of founder William Marsh Rice, includes Ralph Adams Cram’s masterpiece, the asymmetrical Lovett Hall, the original administrative building; Fondren Library; Herzstein Hall; the original physics building and home to the largest amphitheater on campus; Sewall Hall for the social sciences and arts; Rayzor Hall for the languages; and Anderson Hall of the Architecture department. The Humanities Building winner of several architectural awards is immediately adjacent to the main quad. Further west lies a quad surrounded by McNair Hall of the Jones Business School; the Baker Institute; and Alice Pratt Brown Hall of the Shepherd School of Music. These two quads are surrounded by the university’s main access road, a one-way loop referred to as the “inner loop”. In the Engineering Quad, a trinity of sculptures by Michael Heizer, collectively entitled 45 Degrees; 90 Degrees; 180 Degrees are flanked by Abercrombie Laboratory; the Cox Building; and the Mechanical Laboratory housing the Electrical; Mechanical; and Earth Science/Civil Engineering departments respectively. Duncan Hall is the latest addition to this quad providing new offices for the Computer Science; Computational and Applied Math; Electrical and Computer Engineering; and Statistics departments.

    Roughly three-quarters of Rice’s undergraduate population lives on campus. Housing is divided among eleven residential colleges which form an integral part of student life at the university The colleges are named for university historical figures and benefactors.While there is wide variation in their appearance; facilities; and dates of founding are an important source of identity for Rice students functioning as dining halls; residence halls; sports teams among other roles. Rice does not have or endorse a Greek system with the residential college system taking its place. Five colleges: McMurtry; Duncan; Martel; Jones; and Brown are located on the north side of campus across from the “South Colleges”; Baker; Will Rice; Lovett, Hanszen; Sid Richardson; and Wiess on the other side of the Academic Quadrangle. Of the eleven colleges Baker is the oldest originally built in 1912 and the twin Duncan and McMurtry colleges are the newest and opened for the first time for the 2009–10 school year. Will Rice; Baker; and Lovett colleges are undergoing renovation to expand their dining facilities as well as the number of rooms available for students.

    The on-campus football facility-Rice Stadium opened in 1950 with a capacity of 70000 seats. After improvements in 2006 the stadium is currently configured to seat 47,000 for football but can readily be reconfigured to its original capacity of 70000, more than the total number of Rice alumni living and deceased. The stadium was the site of Super Bowl VIII and a speech by John F. Kennedy on September 12 1962 in which he challenged the nation to send a man to the moon by the end of the decade. The recently renovated Tudor Fieldhouse formerly known as Autry Court is home to the basketball and volleyball teams. Other stadia include the Rice Track/Soccer Stadium and the Jake Hess Tennis Stadium. A new Rec Center now houses the intramural sports offices and provide an outdoor pool and training and exercise facilities for all Rice students while athletics training will solely be held at Tudor Fieldhouse and the Rice Football Stadium.

    The university and Houston Independent School District jointly established The Rice School-a kindergarten through 8th grade public magnet school in Houston. The school opened in August 1994. Through Cy-Fair ISD Rice University offers a credit course based summer school for grades 8 through 12. They also have skills based classes during the summer in the Rice Summer School.

    Innovation District

    In early 2019 Rice announced the site where the abandoned Sears building in Midtown Houston stood along with its surrounding area would be transformed into the “The Ion” the hub of the 16-acre South Main Innovation District. President of Rice David Leebron stated “We chose the name Ion because it’s from the Greek ienai, which means ‘go’. We see it as embodying the ever-forward motion of discovery, the spark at the center of a truly original idea.”

    Students of Rice and other Houston-area colleges and universities making up the Student Coalition for a Just and Equitable Innovation Corridor are advocating for a Community Benefits Agreement (CBA)-a contractual agreement between a developer and a community coalition. Residents of neighboring Third Ward and other members of the Houston Coalition for Equitable Development Without Displacement (HCEDD) have faced consistent opposition from the City of Houston and Rice Management Company to a CBA as traditionally defined in favor of an agreement between the latter two entities without a community coalition signatory.

    Organization

    Rice University is chartered as a non-profit organization and is governed by a privately appointed board of trustees. The board consists of a maximum of 25 voting members who serve four-year terms. The trustees serve without compensation and a simple majority of trustees must reside in Texas including at least four within the greater Houston area. The board of trustees delegates its power by appointing a president to serve as the chief executive of the university. David W. Leebron was appointed president in 2004 and succeeded Malcolm Gillis who served since 1993. The provost six vice presidents and other university officials report to the president. The president is advised by a University Council composed of the provost, eight members of the Faculty Council, two staff members, one graduate student, and two undergraduate students. The president presides over a Faculty Council which has the authority to alter curricular requirements, establish new degree programs, and approve candidates for degrees.

    The university’s academics are organized into several schools. Schools that have undergraduate and graduate programs include:

    The Rice University School of Architecture
    The George R. Brown School of Engineering
    The School of Humanities
    The Shepherd School of Music
    The Wiess School of Natural Sciences
    The Rice University School of Social Sciences

    Two schools have only graduate programs:

    The Jesse H. Jones Graduate School of Management
    The Susanne M. Glasscock School of Continuing Studies

    Rice’s undergraduate students benefit from a centralized admissions process which admits new students to the university as a whole, rather than a specific school (the schools of Music and Architecture are decentralized). Students are encouraged to select the major path that best suits their desires; a student can later decide that they would rather pursue study in another field or continue their current coursework and add a second or third major. These transitions are designed to be simple at Rice with students not required to decide on a specific major until their sophomore year of study.

    Rice’s academics are organized into six schools which offer courses of study at the graduate and undergraduate level, with two more being primarily focused on graduate education, while offering select opportunities for undergraduate students. Rice offers 360 degrees in over 60 departments. There are 40 undergraduate degree programs, 51 masters programs, and 29 doctoral programs.

    Faculty members of each of the departments elect chairs to represent the department to each School’s dean and the deans report to the Provost who serves as the chief officer for academic affairs.

    Rice Management Company

    The Rice Management Company manages the $6.5 billion Rice University endowment (June 2019) and $957 million debt. The endowment provides 40% of Rice’s operating revenues. Allison Thacker is the President and Chief Investment Officer of the Rice Management Company, having joined the university in 2011.

    Academics

    Rice is a medium-sized highly residential research university. The majority of enrollments are in the full-time four-year undergraduate program emphasizing arts & sciences and professions. There is a high graduate coexistence with the comprehensive graduate program and a very high level of research activity. It is accredited by the Southern Association of Colleges and Schools Commission on Colleges (US) as well as the professional accreditation agencies for engineering, management, and architecture.

    Each of Rice’s departments is organized into one of three distribution groups, and students whose major lies within the scope of one group must take at least 3 courses of at least 3 credit hours each of approved distribution classes in each of the other two groups, as well as completing one physical education course as part of the LPAP (Lifetime Physical Activity Program) requirement. All new students must take a Freshman Writing Intensive Seminar (FWIS) class, and for students who do not pass the university’s writing composition examination (administered during the summer before matriculation), FWIS 100, a writing class, becomes an additional requirement.

    The majority of Rice’s undergraduate degree programs grant B.S. or B.A. degrees. Rice has recently begun to offer minors in areas such as business, energy and water sustainability, and global health.

    Student body

    As of fall 2014, men make up 52% of the undergraduate body and 64% of the professional and post-graduate student body. The student body consists of students from all 50 states, including the District of Columbia, two U.S. Territories, and 83 foreign countries. Forty percent of degree-seeking students are from Texas.

    Research centers and resources

    Rice is noted for its applied science programs in the fields of nanotechnology, artificial heart research, structural chemical analysis, signal processing and space science.

    Rice Alliance for Technology and Entrepreneurship – supports entrepreneurs and early-stage technology ventures in Houston and Texas through education, collaboration, and research, ranked No. 1 among university business incubators.
    Baker Institute for Public Policy – a leading nonpartisan public policy think-tank
    BioScience Research Collaborative (BRC) – interdisciplinary, cross-campus, and inter-institutional resource between Rice University and Texas Medical Center
    Boniuk Institute – dedicated to religious tolerance and advancing religious literacy, respect and mutual understanding
    Center for African and African American Studies – fosters conversations on topics such as critical approaches to race and racism, the nature of diasporic histories and identities, and the complexity of Africa’s past, present and future
    Chao Center for Asian Studies – research hub for faculty, students and post-doctoral scholars working in Asian studies
    Center for the Study of Women, Gender, and Sexuality (CSWGS) – interdisciplinary academic programs and research opportunities, including the journal Feminist Economics
    Data to Knowledge Lab (D2K) – campus hub for experiential learning in data science
    Digital Signal Processing (DSP) – center for education and research in the field of digital signal processing
    Ethernest Hackerspace – student-run hackerspace for undergraduate engineering students sponsored by the ECE department and the IEEE student chapter
    Humanities Research Center (HRC) – identifies, encourages, and funds innovative research projects by faculty, visiting scholars, graduate, and undergraduate students in the School of Humanities and beyond
    Institute of Biosciences and Bioengineering (IBB) – facilitates the translation of interdisciplinary research and education in biosciences and bioengineering
    Ken Kennedy Institute for Information Technology – advances applied interdisciplinary research in the areas of computation and information technology
    Kinder Institute for Urban Research – conducts the Houston Area Survey, “the nation’s longest running study of any metropolitan region’s economy, population, life experiences, beliefs and attitudes”
    Laboratory for Nanophotonics (LANP) – a resource for education and research breakthroughs and advances in the broad, multidisciplinary field of nanophotonics
    Moody Center for the Arts – experimental arts space featuring studio classrooms, maker space, audiovisual editing booths, and a gallery and office space for visiting national and international artists
    OpenStax CNX (formerly Connexions) and OpenStax – an open source platform and open access publisher, respectively, of open educational resources
    Oshman Engineering Design Kitchen (OEDK) – space for undergraduate students to design, prototype and deploy solutions to real-world engineering challenges
    Rice Cinema – an independent theater run by the Visual and Dramatic Arts department at Rice which screens documentaries, foreign films, and experimental cinema and hosts film festivals and lectures since 1970
    Rice Center for Engineering Leadership (RCEL) – inspires, educates, and develops ethical leaders in technology who will excel in research, industry, non-engineering career paths, or entrepreneurship
    Religion and Public Life Program (RPLP) – a research, training and outreach program working to advance understandings of the role of religion in public life
    Rice Design Alliance (RDA) – outreach and public programs of the Rice School of Architecture
    Rice Center for Quantum Materials (RCQM) – organization dedicated to research and higher education in areas relating to quantum phenomena
    Rice Neuroengineering Initiative (NEI) – fosters research collaborations in neural engineering topics
    Rice Space Institute (RSI) – fosters programs in all areas of space research
    Smalley-Curl Institute for Nanoscale Science and Technology (SCI) – the nation’s first nanotechnology center
    Welch Institute for Advanced Materials – collaborative research institute to support the foundational research for discoveries in materials science, similar to the model of Salk Institute and Broad Institute
    Woodson Research Center Special Collections & Archives – publisher of print and web-based materials highlighting the department’s primary source collections such as the Houston African American, Asian American, and Jewish History Archives, University Archives, rare books, and hip hop/rap music-related materials from the Swishahouse record label and Houston Folk Music Archive, etc.

    Student life

    Situated on nearly 300 acres (120 ha) in the center of Houston’s Museum District and across the street from the city’s Hermann Park, Rice is a green and leafy refuge; an oasis of learning convenient to the amenities of the nation’s fourth-largest city. Rice’s campus adjoins Hermann Park, the Texas Medical Center, and a neighborhood commercial center called Rice Village. Hermann Park includes the Houston Museum of Natural Science, the Houston Zoo, Miller Outdoor Theatre and an 18-hole municipal golf course. NRG Park, home of NRG Stadium and the Astrodome, is two miles (3 km) south of the campus. Among the dozen or so museums in the Museum District was (until May 14, 2017) the Rice University Art Gallery, open during the school year from 1995 until it closed in 2017. Easy access to downtown’s theater and nightlife district and to Reliant Park is provided by the Houston METRORail system, with a station adjacent to the campus’s main gate. The campus recently joined the Zipcar program with two vehicles to increase the transportation options for students and staff who need but currently don’t utilize a vehicle.

    Residential colleges

    In 1957, Rice University implemented a residential college system, which was proposed by the university’s first president, Edgar Odell Lovett. The system was inspired by existing systems in place at University of Oxford (UK) and University of Cambridge (UK) and at several other universities in the United States, most notably Yale University (US). The existing residences known as East, South, West, and Wiess Halls became Baker, Will Rice, Hanszen, and Wiess Colleges, respectively.

    List of residential colleges:

    Baker College, named in honor of Captain James A. Baker, friend and attorney of William Marsh Rice, and first chair of the Rice Board of Governors.
    Will Rice College, named for William M. Rice, Jr., the nephew of the university’s founder, William Marsh Rice.
    Hanszen College, named for Harry Clay Hanszen, benefactor to the university and chairman of the Rice Board of Governors from 1946 to 1950.
    Wiess College, named for Harry Carothers Wiess (1887–1948), one of the founders and one-time president of Humble Oil, now ExxonMobil.
    Jones College, named for Mary Gibbs Jones, wife of prominent Houston philanthropist Jesse Holman Jones.
    Brown College, named for Margaret Root Brown by her in-laws, George R. Brown.
    Lovett College, named after the university’s first president, Edgar Odell Lovett.
    Sid Richardson College, named for the Sid Richardson Foundation, which was established by Texas oilman, cattleman, and philanthropist Sid W. Richardson.
    Martel College, named for Marian and Speros P. Martel, was built in 2002.
    McMurtry College, named for Rice alumni Burt and Deedee McMurtry, Silicon Valley venture capitalists.
    Duncan College, named for Charles Duncan, Jr., Secretary of Energy.

    Much of the social and academic life as an undergraduate student at Rice is centered around residential colleges. Each residential college has its own cafeteria (serveries) and each residential college has study groups and its own social practices.

    Although each college is composed of a full cross-section of students at Rice, they have over time developed their own traditions and “personalities”. When students matriculate they are randomly assigned to one of the eleven colleges, although “legacy” exceptions are made for students whose siblings or parents have attended Rice. Students generally remain members of the college that they are assigned to for the duration of their undergraduate careers, even if they move off-campus at any point. Students are guaranteed on-campus housing for freshman year and two of the next three years; each college has its own system for determining allocation of the remaining spaces, collectively known as “Room Jacking”. Students develop strong loyalties to their college and maintain friendly rivalry with other colleges, especially during events such as Beer Bike Race and O-Week. Colleges keep their rivalries alive by performing “jacks,” or pranks, on each other, especially during O-Week and Willy Week. During Matriculation, Commencement, and other formal academic ceremonies, the colleges process in the order in which they were established.

    Student-run media

    Rice has a weekly student newspaper (The Rice Thresher), a yearbook (The Campanile), college radio station (KTRU Rice Radio), and now defunct, campus-wide student television station (RTV5). They are based out of the RMC student center. In addition, Rice hosts several student magazines dedicated to a range of different topics; in fact, the spring semester of 2008 saw the birth of two such magazines, a literary sex journal called Open and an undergraduate science research magazine entitled Catalyst.

    The Rice Thresher is published every Wednesday and is ranked by Princeton Review as one of the top campus newspapers nationally for student readership. It is distributed around campus, and at a few other local businesses and has a website. The Thresher has a small, dedicated staff and is known for its coverage of campus news, open submission opinion page, and the satirical Backpage, which has often been the center of controversy. The newspaper has won several awards from the College Media Association, Associated Collegiate Press and Texas Intercollegiate Press Association.

    The Rice Campanile was first published in 1916 celebrating Rice’s first graduating class. It has published continuously since then, publishing two volumes in 1944 since the university had two graduating classes due to World War II. The website was created sometime in the early to mid 2000s. The 2015 won the first place Pinnacle for best yearbook from College Media Association.

    KTRU Rice Radio is the student-run radio station. Though most DJs are Rice students, anyone is allowed to apply. It is known for playing genres and artists of music and sound unavailable on other radio stations in Houston, and often, the US. The station takes requests over the phone or online. In 2000 and 2006, KTRU won Houston Press’ Best Radio Station in Houston. In 2003, Rice alum and active KTRU DJ DL’s hip-hip show won Houston PressBest Hip-hop Radio Show. On August 17, 2010, it was announced that Rice University had been in negotiations to sell the station’s broadcast tower, FM frequency and license to the University of Houston System to become a full-time classical music and fine arts programming station. The new station, KUHA, would be operated as a not-for-profit outlet with listener supporters. The FCC approved the sale and granted the transfer of license to the University of Houston System on April 15, 2011, however, KUHA proved to be an even larger failure and so after four and a half years of operation, The University of Houston System announced that KUHA’s broadcast tower, FM frequency and license were once again up for sale in August 2015. KTRU continued to operate much as it did previously, streaming live on the Internet, via apps, and on HD2 radio using the 90.1 signal. Under student leadership, KTRU explored the possibility of returning to FM radio for a number of years. In spring 2015, KTRU was granted permission by the FCC to begin development of a new broadcast signal via LPFM radio. On October 1, 2015, KTRU made its official return to FM radio on the 96.1 signal. While broadcasting on HD2 radio has been discontinued, KTRU continues to broadcast via internet in addition to its LPFM signal.

    RTV5 is a student-run television network available as channel 5 on campus. RTV5 was created initially as Rice Broadcast Television in 1997; RBT began to broadcast the following year in 1998, and aired its first live show across campus in 1999. It experienced much growth and exposure over the years with successful programs like Drinking with Phil, The Meg & Maggie Show, which was a variety and call-in show, a weekly news show, and extensive live coverage in December 2000 of the shut down of KTRU by the administration. In spring 2001, the Rice undergraduate community voted in the general elections to support RBT as a blanket tax organization, effectively providing a yearly income of $10,000 to purchase new equipment and provide the campus with a variety of new programming. In the spring of 2005, RBT members decided the station needed a new image and a new name: Rice Television 5. One of RTV5’s most popular shows was the 24-hour show, where a camera and couch placed in the RMC stayed on air for 24 hours. One such show is held in fall and another in spring, usually during a weekend allocated for visits by prospective students. RTV5 has a video on demand site at rtv5.rice.edu. The station went off the air in 2014 and changed its name to Rice Video Productions. In 2015 the group’s funding was threatened, but ultimately maintained. In 2016 the small student staff requested to no longer be a blanket-tax organization. In the fall of 2017, the club did not register as a club.

    The Rice Review, also known as R2, is a yearly student-run literary journal at Rice University that publishes prose, poetry, and creative nonfiction written by undergraduate students, as well as interviews. The journal was founded in 2004 by creative writing professor and author Justin Cronin.

    The Rice Standard was an independent, student-run variety magazine modeled after such publications as The New Yorker and Harper’s. Prior to fall 2009, it was regularly published three times a semester with a wide array of content, running from analyses of current events and philosophical pieces to personal essays, short fiction and poetry. In August 2009, The Standard transitioned to a completely online format with the launch of their redesigned website, http://www.ricestandard.org. The first website of its kind on Rice’s campus, The Standard featured blog-style content written by and for Rice students. The Rice Standard had around 20 regular contributors, and the site features new content every day (including holidays). In 2017 no one registered The Rice Standard as a club within the university.

    Open, a magazine dedicated to “literary sex content,” predictably caused a stir on campus with its initial publication in spring 2008. A mixture of essays, editorials, stories and artistic photography brought Open attention both on campus and in the Houston Chronicle. The third and last annual edition of Open was released in spring of 2010.

    Vahalla is the Graduate Student Association on-campus bar under the steps of the chemistry building.

    Athletics

    Rice plays in NCAA Division I athletics and is part of Conference USA. Rice was a member of the Western Athletic Conference before joining Conference USA in 2005. Rice is the second-smallest school, measured by undergraduate enrollment, competing in NCAA Division I FBS football, only ahead of Tulsa.

    The Rice baseball team won the 2003 College World Series, defeating Stanford, giving Rice its only national championship in a team sport. The victory made Rice University the smallest school in 51 years to win a national championship at the highest collegiate level of the sport. The Rice baseball team has played on campus at Reckling Park since the 2000 season. As of 2010, the baseball team has won 14 consecutive conference championships in three different conferences: the final championship of the defunct Southwest Conference, all nine championships while a member of the Western Athletic Conference, and five more championships in its first five years as a member of Conference USA. Additionally, Rice’s baseball team has finished third in both the 2006 and 2007 College World Series tournaments. Rice now has made six trips to Omaha for the CWS. In 2004, Rice became the first school ever to have three players selected in the first eight picks of the MLB draft when Philip Humber, Jeff Niemann, and Wade Townsend were selected third, fourth, and eighth, respectively. In 2007, Joe Savery was selected as the 19th overall pick.

    Rice has been very successful in women’s sports in recent years. In 2004–05, Rice sent its women’s volleyball, soccer, and basketball teams to their respective NCAA tournaments. The women’s swim team has consistently brought at least one member of their team to the NCAA championships since 2013. In 2005–06, the women’s soccer, basketball, and tennis teams advanced, with five individuals competing in track and field. In 2006–07, the Rice women’s basketball team made the NCAA tournament, while again five Rice track and field athletes received individual NCAA berths. In 2008, the women’s volleyball team again made the NCAA tournament. In 2011 the Women’s Swim team won their first conference championship in the history of the university. This was an impressive feat considering they won without having a diving team. The team repeated their C-USA success in 2013 and 2014. In 2017, the women’s basketball team, led by second-year head coach Tina Langley, won the Women’s Basketball Invitational, defeating UNC-Greensboro 74–62 in the championship game at Tudor Fieldhouse. Though not a varsity sport, Rice’s ultimate frisbee women’s team, named Torque, won consecutive Division III national championships in 2014 and 2015.

    In 2006, the football team qualified for its first bowl game since 1961, ending the second-longest bowl drought in the country at the time. On December 22, 2006, Rice played in the New Orleans Bowl in New Orleans, Louisiana against the Sun Belt Conference champion, Troy. The Owls lost 41–17. The bowl appearance came after Rice had a 14-game losing streak from 2004–05 and went 1–10 in 2005. The streak followed an internally authorized 2003 McKinsey report that stated football alone was responsible for a $4 million deficit in 2002. Tensions remained high between the athletic department and faculty, as a few professors who chose to voice their opinion were in favor of abandoning the football program. The program success in 2006, the Rice Renaissance, proved to be a revival of the Owl football program, quelling those tensions. David Bailiff took over the program in 2007 and has remained head coach. Jarett Dillard set an NCAA record in 2006 by catching a touchdown pass in 13 consecutive games and took a 15-game overall streak into the 2007 season.

    In 2008, the football team posted a 9-3 regular season, capping off the year with a 38–14 victory over Western Michigan University (US) in the Texas Bowl. The win over Western Michigan marked the Owls’ first bowl win in 45 years.

    Rice Stadium also serves as the performance venue for the university’s Marching Owl Band, or “MOB.” Despite its name, the MOB is a scatter band that focuses on performing humorous skits and routines rather than traditional formation marching.

    Rice Owls men’s basketball won 10 conference titles in the former Southwest Conference (1918, 1935*, 1940, 1942*, 1943*, 1944*, 1945, 1949*, 1954*, 1970; * denotes shared title). Most recently, guard Morris Almond was drafted in the first round of the 2007 NBA Draft by the Utah Jazz. Rice named former Cal Bears head coach Ben Braun as head basketball coach to succeed Willis Wilson, fired after Rice finished the 2007–2008 season with a winless (0-16) conference record and overall record of 3-27.

    Rice’s mascot is Sammy the Owl. In previous decades, the university kept several live owls on campus in front of Lovett College, but this practice has been discontinued, due to public pressure over the welfare of the owls.

    Rice also has a 12-member coed cheerleading squad and a coed dance team, both of which perform at football and basketball games throughout the year.

     
  • richardmitnick 7:56 pm on August 19, 2021 Permalink | Reply
    Tags: "Electron–electron and spin–orbit interactions compete to control the electron", , Electrons have a property called spin which can be crudely thought of as the rotation of an electron about an axis., , , Spintronics   

    From RIKEN [理研](JP): “Electron–electron and spin–orbit interactions compete to control the electron” 

    RIKEN bloc

    From RIKEN [理研](JP)

    Aug. 19, 2021

    The interactions that compete to control electron spin can give rise to novel electronic states useful for future quantum technologies.

    1
    Figure 1: Electron spin is influenced by both the electron’s motion, via spin–orbit coupling, and interactions with other electrons, through the Coulomb effect. (Image prepared by Ms. Mari Ishida of RIKEN.) © 2021.

    In a finding that will help to identify exotic quantum states, RIKEN physicists have seen strongly competing factors that affect an electron’s behavior in a high-quality quantum material [1].

    Electrons have a property called spin which can be crudely thought of as the rotation of an electron about an axis. As an electron moves, its motion and spin can become linked through an effect known as spin–orbit coupling. This effect is useful because it offers a way to externally control the motion of an electron depending on its spin—a vital ability for an emerging technology called spintronics, which is seeking to use electron spin to realize low-power-consumption information processing.

    Spin–orbit coupling is a complex mix of quantum physics and relativity, but it becomes a little easier to understand by envisioning a round soccer ball. “If a soccer player kicks the ball, it flies on a straight trajectory,” explains Denis Maryenko of the RIKEN Center for Emergent Matter Science. “But if the player gives the ball some rotation, or spin, its path bends.” The ball’s trajectory and its spinning motion are connected. If its spinning direction is reversed, the ball’s path will bend in the opposite direction.

    Unlike soccer balls, electrons also interact with each other: two negatively charged particles will repel each other, for example. This mutual repulsion and the spin–orbit interaction compete with each other: the former can act to align an electron’s spin with that of other electrons, whereas the latter tries to align an electron’s spin with its motion.

    “This interplay has recently attracted a lot of interest, since it could lead to the emergence of novel electronic and spin phases, which may be used in future quantum technologies,” says Maryenko. “It is thus important to understand the fundamentals of the interplay.” But it is incredibly difficult to identify both effects at the same time.

    Now, Maryenko and his colleagues have succeeded in disentangling the two effects.

    They looked at electrons trapped between two semiconductors, magnesium zinc oxide and zinc oxide. Since the system had very few atomic impurities, there was a strong interaction between electrons. And the researchers could control the strength of the spin–orbit coupling by varying the magnesium content. “We looked carefully at how the sample resistance changed when we applied a magnetic field,” says Maryenko. In this way, they were able to identify signatures of both spin–orbit and the mutual repulsion due to the electrons’ charges.

    This high-quality material system thus represents a great resource for testing theoretical predictions and it opens a path to develop spintronic phenomena in strong-electron-correlation regimes.

    [1] Science paper: Nature Communications

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    RIKEN campus

    RIKEN [理研](JP) is Japan’s largest comprehensive research institution renowned for high-quality research in a diverse range of scientific disciplines. Founded in 1917 as a private research foundation in Tokyo, RIKEN has grown rapidly in size and scope, today encompassing a network of world-class research centers and institutes across Japan.

    Riken (Institute of Physical and Chemical Research) [理研], formally Rikagaku Kenkyūjo (理化学研究所)(JP) (full name in Japanese Kokuritsu Kenkyū Kaihatsu Hōjin Rikagaku Kenkyūsho (国立研究開発法人理化学研究所) is a large scientific research institute in Japan. Founded in 1917, it now has about 3,000 scientists on seven campuses across Japan, including the main site at Wakō, Saitama Prefecture, just outside Tokyo. Riken is a Designated National Research and Development Institute, and was formerly an Independent Administrative Institution.

    Riken conducts research in many areas of science including physics; chemistry; biology; genomics; medical science; engineering; high-performance computing and computational science and ranging from basic research to practical applications with 485 partners worldwide. It is almost entirely funded by the Japanese government, and its annual budget is about ¥88 billion (US$790 million).

    Organizational structure:

    The main divisions of Riken are listed here. Purely administrative divisions are omitted.

    Headquarters (mostly in Wako)
    Wako Branch
    Center for Emergent Matter Science (research on new materials for reduced power consumption)
    Center for Sustainable Resource Science (research toward a sustainable society)
    Nishina Center for Accelerator-Based Science (site of the Radioactive Isotope Beam Factory, a heavy-ion accelerator complex)
    Center for Brain Science
    Center for Advanced Photonics (research on photonics including terahertz radiation)
    Research Cluster for Innovation
    Cluster for Pioneering Research (chief scientists)
    Interdisciplinary Theoretical and Mathematical Sciences Program
    Tokyo Branch
    Center for Advanced Intelligence Project (research on artificial intelligence)
    Tsukuba Branch
    BioResource Research Center
    Harima Institute
    Riken SPring-8 Center (site of the SPring-8 synchrotron and the SACLA x-ray free electron laser)

    RIKEN/HARIMA (JP) X-ray Free Electron Laser

    Yokohama Branch (site of the Yokohama Nuclear magnetic resonance facility)
    Center for Sustainable Resource Science
    Center for Integrative Medical Sciences (research toward personalized medicine)
    Center for Biosystems Dynamics Research (also based in Kobe and Osaka) [6]
    Program for Drug Discovery and Medical Technology Platform
    Structural Biology Laboratory
    Sugiyama Laboratory
    Kobe Branch
    Center for Biosystems Dynamics Research (developmental biology and nuclear medicine medical imaging techniques)
    Center for Computational Science (R-CCS, home of the K computer and The post-K (Fugaku) computer development plan)

     
  • richardmitnick 10:18 am on July 20, 2021 Permalink | Reply
    Tags: "Main Attraction-Scientists Create World’s Thinnest Magnet", 2D magnetism possible at room temperature, , In a final step the graphene is burned away-leaving behind just a single atomic layer of cobalt-doped zinc-oxide., , Spintronics, The researchers synthesized the new 2D magnet – called a cobalt-doped van der Waals zinc-oxide magnet – from a solution of graphene oxide; zinc; and cobalt., This development opens up every single atom for examination.   

    From DOE’s Lawrence Berkeley National Laboratory (US) and University of California-Berkeley (US) : “Main Attraction-Scientists Create World’s Thinnest Magnet” 

    From DOE’s Lawrence Berkeley National Laboratory (US)

    and

    University of California-Berkeley (US)

    July 20, 2021
    Theresa Duque
    tnduque@lbl.gov
    (510) 495-2418

    A one-atom-thin 2D magnet developed by Berkeley Lab and UC Berkeley could advance new applications in computing and electronics.

    1
    Illustration of magnetic coupling in a cobalt-doped zinc-oxide monolayer. Red, blue, and yellow spheres represent cobalt, oxygen, and zinc atoms, respectively. Credit: Berkeley Lab.

    The development of an ultrathin magnet that operates at room temperature could lead to new applications in computing and electronics – such as high-density, compact spintronic memory devices – and new tools for the study of quantum physics.

    The ultrathin magnet, which was recently reported in the journal Nature Communications, could make big advances in next-gen memory devices, computing, spintronics, and quantum physics. It was discovered by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley.

    “We’re the first to make a room-temperature 2D magnet that is chemically stable under ambient conditions,” said senior author Jie Yao, a faculty scientist in Berkeley Lab’s Materials Sciences Division and associate professor of materials science and engineering at UC Berkeley.

    “This discovery is exciting because it not only makes 2D magnetism possible at room temperature, but it also uncovers a new mechanism to realize 2D magnetic materials,” added Rui Chen, a UC Berkeley graduate student in the Yao Research Group and lead author on the study.

    The magnetic component of today’s memory devices is typically made of magnetic thin films. But at the atomic level, these materials are still three-dimensional – hundreds or thousands of atoms thick. For decades, researchers have searched for ways to make thinner and smaller 2D magnets and thus enable data to be stored at a much higher density.

    Previous achievements in the field of 2D magnetic materials have brought promising results. But these early 2D magnets lose their magnetism and become chemically unstable at room temperature.

    “State-of-the-art 2D magnets need very low temperatures to function. But for practical reasons, a data center needs to run at room temperature,” Yao said. “Our 2D magnet is not only the first that operates at room temperature or higher, but it is also the first magnet to reach the true 2D limit: It’s as thin as a single atom!”

    The researchers say that their discovery will also enable new opportunities to study quantum physics. “It opens up every single atom for examination, which may reveal how quantum physics governs each single magnetic atom and the interactions between them,” Yao said.

    The making of a 2D magnet that can take the heat.

    The researchers synthesized the new 2D magnet – called a cobalt-doped van der Waals zinc-oxide magnet – from a solution of graphene oxide; zinc; and cobalt.

    Just a few hours of baking in a conventional lab oven transformed the mixture into a single atomic layer of zinc-oxide with a smattering of cobalt atoms sandwiched between layers of graphene.

    In a final step the graphene is burned away-leaving behind just a single atomic layer of cobalt-doped zinc-oxide.

    “With our material, there are no major obstacles for industry to adopt our solution-based method,” said Yao. “It’s potentially scalable for mass production at lower costs.”

    To confirm that the resulting 2D film is just one atom thick, Yao and his team conducted scanning electron microscopy experiments at Berkeley Lab’s Molecular Foundry [below] to identify the material’s morphology, and transmission electron microscopy (TEM) imaging to probe the material atom by atom.

    X-ray experiments at Berkeley Lab’s Advanced Light Source characterized the 2D material’s magnetic parameters under high temperature.

    DOE’s Lawrence Berkeley National Laboratory (US) Advanced Light Source.

    Additional X-ray experiments at DOE’s SLAC National Accelerator Laboratory’s (US) Stanford Synchrotron Radiation Lightsource verified the electronic and crystal structures of the synthesized 2D magnets.

    SLAC National Accelerator Laboratory (US) Stanford Synchrotron Radiation Lightsource SSRL

    And at DOE’s Argonne National Laboratory’s (US) Center for Nanoscale Materials, the researchers employed TEM to image the 2D material’s crystal structure and chemical composition.

    3
    Argonne National Laboratory’s Center for Nanoscale Materials

    The researchers found that the graphene-zinc-oxide system becomes weakly magnetic with a 5-6% concentration of cobalt atoms. Increasing the concentration of cobalt atoms to about 12% results in a very strong magnet.

    To their surprise, a concentration of cobalt atoms exceeding 15% shifts the 2D magnet into an exotic quantum state of “frustration,” whereby different magnetic states within the 2D system are in competition with each other.

    And unlike previous 2D magnets, which lose their magnetism at room temperature or above, the researchers found that the new 2D magnet not only works at room temperature but also at 100 degrees Celsius (212 degrees Fahrenheit).

    “Our 2D magnetic system shows a distinct mechanism compared to previous 2D magnets,” said Chen. “And we think this unique mechanism is due to the free electrons in zinc oxide.”

    True north: Free electrons keep magnetic atoms on track

    When you command your computer to save a file, that information is stored as a series of ones and zeroes in the computer’s magnetic memory, such as the magnetic hard drive or a flash memory.

    And like all magnets, magnetic memory devices contain microscopic magnets with two poles – north and south, the orientations of which follow the direction of an external magnetic field. Data is written or encoded when these tiny magnets are flipped to the desired directions.

    According to Chen, zinc oxide’s free electrons could act as an intermediary that ensures the magnetic cobalt atoms in the new 2D device continue pointing in the same direction – and thus stay magnetic – even when the host, in this case the semiconductor zinc oxide, is a nonmagnetic material.

    “Free electrons are constituents of electric currents. They move in the same direction to conduct electricity,” Yao added, comparing the movement of free electrons in metals and semiconductors to the flow of water molecules in a stream of water.

    The new material – which can be bent into almost any shape without breaking, and is a million times thinner than a sheet of paper – could help advance the application of spin electronics or spintronics, a new technology that uses the orientation of an electron’s spin rather than its charge to encode data. “Our 2D magnet may enable the formation of ultra-compact spintronic devices to engineer the spins of the electrons,” Chen said.

    “I believe that the discovery of this new, robust, truly two-dimensional magnet at room temperature is a genuine breakthrough,” said co-author Robert Birgeneau, a faculty senior scientist in Berkeley Lab’s Materials Sciences Division and professor of physics at UC Berkeley who co-led the study.

    “Our results are even better than what we expected, which is really exciting. Most of the time in science, experiments can be very challenging,” Yao said. “But when you finally realize something new, it’s always very fulfilling.”

    Co-authors on the paper include researchers from Berkeley Lab, including Alpha N’Diaye and Padraic Shafer of the Advanced Light Source; University of California-Berkeley (US); University of California-Riverside (US); DOE’s Argonne National Laboratory (US); and Nanjing University [南京大學] (CN) and the University of Electronic Science and Technology of China [电子科技大学](CN).

    The Advanced Light Source and Molecular Foundry are DOE national user facilities at Berkeley Lab.

    The Stanford Synchrotron Radiation Lightsource is a DOE national user facility at SLAC National Accelerator Laboratory.

    The Center for Nanoscale Materials is a DOE national user facility at Argonne National Laboratory.

    This work was funded by the DOE Office of Science, the Intel Corporation, and the Bakar Fellows Program at UC Berkeley.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of California-Berkeley US) is a public land-grant research university in Berkeley, California. Established in 1868 as the state’s first land-grant university, it was the first campus of the University of California (US) system and a founding member of the Association of American Universities (US). Its 14 colleges and schools offer over 350 degree programs and enroll some 31,000 undergraduate and 12,000 graduate students. Berkeley is ranked among the world’s top universities by major educational publications.

    Berkeley hosts many leading research institutes, including the Mathematical Sciences Research Institute and the Space Sciences Laboratory. It founded and maintains close relationships with three national laboratories at DOE’s Lawrence Berkeley National Laboratory(US), DOE’s Lawrence Livermore National Laboratory(US) and DOE’s Los Alamos National Lab(US), and has played a prominent role in many scientific advances, from the Manhattan Project and the discovery of 16 chemical elements to breakthroughs in computer science and genomics. Berkeley is also known for student activism and the Free Speech Movement of the 1960s.

    Berkeley alumni and faculty count among their ranks 110 Nobel laureates (34 alumni), 25 Turing Award winners (11 alumni), 14 Fields Medalists, 28 Wolf Prize winners, 103 MacArthur “Genius Grant” recipients, 30 Pulitzer Prize winners, and 19 Academy Award winners. The university has produced seven heads of state or government; five chief justices, including Chief Justice of the United States Earl Warren; 21 cabinet-level officials; 11 governors; and 25 living billionaires. It is also a leading producer of Fulbright Scholars, MacArthur Fellows, and Marshall Scholars. Berkeley alumni, widely recognized for their entrepreneurship, have founded many notable companies.

    Berkeley’s athletic teams compete in Division I of the NCAA, primarily in the Pac-12 Conference, and are collectively known as the California Golden Bears. The university’s teams have won 107 national championships, and its students and alumni have won 207 Olympic medals.

    Made possible by President Lincoln’s signing of the Morrill Act in 1862, the University of California was founded in 1868 as the state’s first land-grant university by inheriting certain assets and objectives of the private College of California and the public Agricultural, Mining, and Mechanical Arts College. Although this process is often incorrectly mistaken for a merger, the Organic Act created a “completely new institution” and did not actually merge the two precursor entities into the new university. The Organic Act states that the “University shall have for its design, to provide instruction and thorough and complete education in all departments of science, literature and art, industrial and professional pursuits, and general education, and also special courses of instruction in preparation for the professions”.

    Ten faculty members and 40 students made up the fledgling university when it opened in Oakland in 1869. Frederick H. Billings, a trustee of the College of California, suggested that a new campus site north of Oakland be named in honor of Anglo-Irish philosopher George Berkeley. The university began admitting women the following year. In 1870, Henry Durant, founder of the College of California, became its first president. With the completion of North and South Halls in 1873, the university relocated to its Berkeley location with 167 male and 22 female students.

    Beginning in 1891, Phoebe Apperson Hearst made several large gifts to Berkeley, funding a number of programs and new buildings and sponsoring, in 1898, an international competition in Antwerp, Belgium, where French architect Émile Bénard submitted the winning design for a campus master plan.

    20th century

    In 1905, the University Farm was established near Sacramento, ultimately becoming the University of California, Davis. In 1919, Los Angeles State Normal School became the southern branch of the University, which ultimately became the University of California, Los Angeles. By 1920s, the number of campus buildings had grown substantially and included twenty structures designed by architect John Galen Howard.

    In 1917, one of the nation’s first ROTC programs was established at Berkeley and its School of Military Aeronautics began training pilots, including Gen. Jimmy Doolittle. Berkeley ROTC alumni include former Secretary of Defense Robert McNamara and Army Chief of Staff Frederick C. Weyand as well as 16 other generals. In 1926, future fleet admiral Chester W. Nimitz established the first Naval ROTC unit at Berkeley.

    In the 1930s, Ernest Lawrence helped establish the Radiation Laboratory (now DOE’s Lawrence Berkeley National Laboratory (US)) and invented the cyclotron, which won him the Nobel physics prize in 1939. Using the cyclotron, Berkeley professors and Berkeley Lab researchers went on to discover 16 chemical elements—more than any other university in the world. In particular, during World War II and following Glenn Seaborg’s then-secret discovery of plutonium, Ernest Orlando Lawrence’s Radiation Laboratory began to contract with the U.S. Army to develop the atomic bomb. Physics professor J. Robert Oppenheimer was named scientific head of the Manhattan Project in 1942. Along with the Lawrence Berkeley National Laboratory, Berkeley founded and was then a partner in managing two other labs, Los Alamos National Laboratory (1943) and Lawrence Livermore National Laboratory (1952).

    By 1942, the American Council on Education ranked Berkeley second only to Harvard University (US) in the number of distinguished departments.

    In 1952, the University of California reorganized itself into a system of semi-autonomous campuses, with each campus given its own chancellor, and Clark Kerr became Berkeley’s first Chancellor, while Sproul remained in place as the President of the University of California.

    Berkeley gained a worldwide reputation for political activism in the 1960s. In 1964, the Free Speech Movement organized student resistance to the university’s restrictions on political activities on campus—most conspicuously, student activities related to the Civil Rights Movement. The arrest in Sproul Plaza of Jack Weinberg, a recent Berkeley alumnus and chair of Campus CORE, in October 1964, prompted a series of student-led acts of formal remonstrance and civil disobedience that ultimately gave rise to the Free Speech Movement, which movement would prevail and serve as precedent for student opposition to America’s involvement in the Vietnam War.

    In 1982, the Mathematical Sciences Research Institute (MSRI) was established on campus with support from the National Science Foundation and at the request of three Berkeley mathematicians — Shiing-Shen Chern, Calvin Moore and Isadore M. Singer. The institute is now widely regarded as a leading center for collaborative mathematical research, drawing thousands of visiting researchers from around the world each year.

    21st century

    In the current century, Berkeley has become less politically active and more focused on entrepreneurship and fundraising, especially for STEM disciplines.

    Modern Berkeley students are less politically radical, with a greater percentage of moderates and conservatives than in the 1960s and 70s. Democrats outnumber Republicans on the faculty by a ratio of 9:1. On the whole, Democrats outnumber Republicans on American university campuses by a ratio of 10:1.

    In 2007, the Energy Biosciences Institute was established with funding from BP and Stanley Hall, a research facility and headquarters for the California Institute for Quantitative Biosciences, opened. The next few years saw the dedication of the Center for Biomedical and Health Sciences, funded by a lead gift from billionaire Li Ka-shing; the opening of Sutardja Dai Hall, home of the Center for Information Technology Research in the Interest of Society; and the unveiling of Blum Hall, housing the Blum Center for Developing Economies. Supported by a grant from alumnus James Simons, the Simons Institute for the Theory of Computing was established in 2012. In 2014, Berkeley and its sister campus, Univerity of California-San Fransisco (US), established the Innovative Genomics Institute, and, in 2020, an anonymous donor pledged $252 million to help fund a new center for computing and data science.

    Since 2000, Berkeley alumni and faculty have received 40 Nobel Prizes, behind only Harvard and Massachusetts Institute of Technology (US) among US universities; five Turing Awards, behind only MIT and Stanford; and five Fields Medals, second only to Princeton University (US). According to PitchBook, Berkeley ranks second, just behind Stanford University, in producing VC-backed entrepreneurs.

    UC Berkeley Seal

    LBNL campus


    Bringing Science Solutions to the World

    In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab) (US) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

    Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (US) and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the UC Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

    Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a University of California-Berkeley (US) physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.

    History

    1931–1941

    The laboratory was founded on August 26, 1931, by Ernest Lawrence, as the Radiation Laboratory of the University of California, Berkeley, associated with the Physics Department. It centered physics research around his new instrument, the cyclotron, a type of particle accelerator for which he was awarded the Nobel Prize in Physics in 1939.

    LBNL 88 inch cyclotron.


    Throughout the 1930s, Lawrence pushed to create larger and larger machines for physics research, courting private philanthropists for funding. He was the first to develop a large team to build big projects to make discoveries in basic research. Eventually these machines grew too large to be held on the university grounds, and in 1940 the lab moved to its current site atop the hill above campus. Part of the team put together during this period includes two other young scientists who went on to establish large laboratories; J. Robert Oppenheimer founded DOE’s Los Alamos Laboratory (US), and Robert Wilson founded Fermi National Accelerator Laboratory(US).

    1942–1950

    Leslie Groves visited Lawrence’s Radiation Laboratory in late 1942 as he was organizing the Manhattan Project, meeting J. Robert Oppenheimer for the first time. Oppenheimer was tasked with organizing the nuclear bomb development effort and founded today’s Los Alamos National Laboratory to help keep the work secret. At the RadLab, Lawrence and his colleagues developed the technique of electromagnetic enrichment of uranium using their experience with cyclotrons. The “calutrons” (named after the University) became the basic unit of the massive Y-12 facility in Oak Ridge, Tennessee. Lawrence’s lab helped contribute to what have been judged to be the three most valuable technology developments of the war (the atomic bomb, proximity fuse, and radar). The cyclotron, whose construction was stalled during the war, was finished in November 1946. The Manhattan Project shut down two months later.

    1951–2018

    After the war, the Radiation Laboratory became one of the first laboratories to be incorporated into the Atomic Energy Commission (AEC) (now Department of Energy (US). The most highly classified work remained at Los Alamos, but the RadLab remained involved. Edward Teller suggested setting up a second lab similar to Los Alamos to compete with their designs. This led to the creation of an offshoot of the RadLab (now the Lawrence Livermore National Laboratory (US)) in 1952. Some of the RadLab’s work was transferred to the new lab, but some classified research continued at Berkeley Lab until the 1970s, when it became a laboratory dedicated only to unclassified scientific research.

    Shortly after the death of Lawrence in August 1958, the UC Radiation Laboratory (both branches) was renamed the Lawrence Radiation Laboratory. The Berkeley location became the Lawrence Berkeley Laboratory in 1971, although many continued to call it the RadLab. Gradually, another shortened form came into common usage, LBNL. Its formal name was amended to Ernest Orlando Lawrence Berkeley National Laboratory in 1995, when “National” was added to the names of all DOE labs. “Ernest Orlando” was later dropped to shorten the name. Today, the lab is commonly referred to as “Berkeley Lab”.

    The Alvarez Physics Memos are a set of informal working papers of the large group of physicists, engineers, computer programmers, and technicians led by Luis W. Alvarez from the early 1950s until his death in 1988. Over 1700 memos are available on-line, hosted by the Laboratory.

    The lab remains owned by the Department of Energy (US), with management from the University of California (US). Companies such as Intel were funding the lab’s research into computing chips.

    Science mission

    From the 1950s through the present, Berkeley Lab has maintained its status as a major international center for physics research, and has also diversified its research program into almost every realm of scientific investigation. Its mission is to solve the most pressing and profound scientific problems facing humanity, conduct basic research for a secure energy future, understand living systems to improve the environment, health, and energy supply, understand matter and energy in the universe, build and safely operate leading scientific facilities for the nation, and train the next generation of scientists and engineers.

    The Laboratory’s 20 scientific divisions are organized within six areas of research: Computing Sciences; Physical Sciences; Earth and Environmental Sciences; Biosciences; Energy Sciences; and Energy Technologies. Berkeley Lab has six main science thrusts: advancing integrated fundamental energy science; integrative biological and environmental system science; advanced computing for science impact; discovering the fundamental properties of matter and energy; accelerators for the future; and developing energy technology innovations for a sustainable future. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab tradition that continues today.

    Berkeley Lab operates five major National User Facilities for the DOE Office of Science (US):

    The Advanced Light Source (ALS) is a synchrotron light source with 41 beam lines providing ultraviolet, soft x-ray, and hard x-ray light to scientific experiments.

    LBNL/ALS


    The ALS is one of the world’s brightest sources of soft x-rays, which are used to characterize the electronic structure of matter and to reveal microscopic structures with elemental and chemical specificity. About 2,500 scientist-users carry out research at ALS every year. Berkeley Lab is proposing an upgrade of ALS which would increase the coherent flux of soft x-rays by two-three orders of magnitude.

    The DOE Joint Genome Institute (US) supports genomic research in support of the DOE missions in alternative energy, global carbon cycling, and environmental management. The JGI’s partner laboratories are Berkeley Lab, DOE’s Lawrence Livermore National Laboratory (US), DOE’s Oak Ridge National Laboratory (US)(ORNL), DOE’s Pacific Northwest National Laboratory (US) (PNNL), and the HudsonAlpha Institute for Biotechnology (US). The JGI’s central role is the development of a diversity of large-scale experimental and computational capabilities to link sequence to biological insights relevant to energy and environmental research. Approximately 1,200 scientist-users take advantage of JGI’s capabilities for their research every year.

    The LBNL Molecular Foundry (US) [above] is a multidisciplinary nanoscience research facility. Its seven research facilities focus on Imaging and Manipulation of Nanostructures; Nanofabrication; Theory of Nanostructured Materials; Inorganic Nanostructures; Biological Nanostructures; Organic and Macromolecular Synthesis; and Electron Microscopy. Approximately 700 scientist-users make use of these facilities in their research every year.

    The DOE’s NERSC National Energy Research Scientific Computing Center (US) is the scientific computing facility that provides large-scale computing for the DOE’s unclassified research programs. Its current systems provide over 3 billion computational hours annually. NERSC supports 6,000 scientific users from universities, national laboratories, and industry.

    DOE’s NERSC National Energy Research Scientific Computing Center(US) at Lawrence Berkeley National Laboratory

    The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

    PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

    NERSC is a DOE Office of Science User Facility.

    The DOE’s Energy Science Network (US) is a high-speed network infrastructure optimized for very large scientific data flows. ESNet provides connectivity for all major DOE sites and facilities, and the network transports roughly 35 petabytes of traffic each month.

    Berkeley Lab is the lead partner in the DOE’s Joint Bioenergy Institute (US) (JBEI), located in Emeryville, California. Other partners are the DOE’s Sandia National Laboratory (US), the University of California (UC) campuses of Berkeley and Davis, the Carnegie Institution for Science (US), and DOE’s Lawrence Livermore National Laboratory (US) (LLNL). JBEI’s primary scientific mission is to advance the development of the next generation of biofuels – liquid fuels derived from the solar energy stored in plant biomass. JBEI is one of three new U.S. Department of Energy (DOE) Bioenergy Research Centers (BRCs).

    Berkeley Lab has a major role in two DOE Energy Innovation Hubs. The mission of the Joint Center for Artificial Photosynthesis (JCAP) is to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide. The lead institution for JCAP is the California Institute of Technology (US) and Berkeley Lab is the second institutional center. The mission of the Joint Center for Energy Storage Research (JCESR) is to create next-generation battery technologies that will transform transportation and the electricity grid. DOE’s Argonne National Laboratory (US) leads JCESR and Berkeley Lab is a major partner.

     
  • richardmitnick 4:00 pm on July 17, 2021 Permalink | Reply
    Tags: "Future information technologies- Topological materials for ultrafast spintronics", , Helmholtz Center for Materials and Energy [Helmholtz-Zentrum Berlin für Materialien und Energie](HZB) (DE), In so-called topological insulators only the electrons that can occupy some specific quantum states are free to move like massless particles on the surface., , Many questions still need to be answered before spintronic devices can be developed., , , Spintronics, The laws of quantum physics rule the microcosm.   

    From Helmholtz Center for Materials and Energy [Helmholtz-Zentrum Berlin für Materialien und Energie](HZB) (DE): “Future information technologies- Topological materials for ultrafast spintronics” 

    From Helmholtz Center for Materials and Energy [Helmholtz-Zentrum Berlin für Materialien und Energie](HZB) (DE)

    16.07.2021

    Dr. Jaime Sánchez-Barriga
    Tel-(030) 8062 – 15695
    Fax-(030) 8062 – 14673
    jaime.sanchez-barriga@helmholtz-berlin.de

    Dr. Oliver Jon Clark
    Tel-(030) 8062 – 15695
    Fax-(030) 8062 – 14673
    oliver.clark@helmholtz-berlin.de

    Press Officer:
    Dr. Antonia Rötger
    Tel-(030) 8062 – 43733
    Fax-(030) 8062 – 42998
    antonia.roetger@helmholtz-berlin.de

    A team led by HZB physicist Dr. Jaime Sánchez-Barriga has gained new insights into the ultrafast response of topological states of matter to femtosecond laser excitation. Using time- and spin-resolved methods at BESSY II, the physicists explored how, after optical excitation, the complex interplay in the behavior of excited electrons in the bulk and on the surface results in unusual spin dynamics.


    BESSY II Synchrotron at Helmholtz Center for Materials and Energy [Helmholtz-Zentrum Berlin für Materialien und Energie](DE)

    The work is an important step on the way to spintronic devices based on topological materials for ultrafast information processing.

    The laws of quantum physics rule the microcosm. They determine, for example, how easily electrons move through a crystal and thus whether the material is a metal, a semiconductor or an insulator. Quantum physics may lead to exotic properties in certain materials: In so-called topological insulators only the electrons that can occupy some specific quantum states are free to move like massless particles on the surface, while this mobility is completely absent for electrons in the bulk. What’s more, the conduction electrons in the “skin” of the material are necessarily spin polarized, and form robust, metallic surface states that could be utilized as channels in which to drive pure spin currents on femtosecond time scales (1 fs= 10^-15 s).

    Exploiting the spin

    These properties open up exciting opportunities to develop new information technologies based on topological materials, such as ultrafast spintronics, by exploiting the spin of the electrons on their surfaces rather than the charge. In particular, optical excitation by femtosecond laser pulses in these materials represents a promising alternative to realize highly efficient, lossless transfer of spin information. Spintronic devices utilizing these properties have the potential of a superior performance, as they would allow to increase the speed of information transport up to frequencies a thousand times faster than in modern electronics.

    However, many questions still need to be answered before spintronic devices can be developed. For example, the details of exactly how the bulk and surface electrons from a topological material respond to the external stimulus i.e., the laser pulse, and the degree of overlap in their collective behaviors on ultrashort time scales.

    The sample: a pure Antimony crystal

    A team led by HZB physicist Dr. Jaime Sánchez-Barriga has now brought new insights into such mechanisms. The team, which has also established a Helmholtz-RSF Joint Research Group in collaboration with colleagues from Lomonosova Moscow State University[Московский государственный университет имени](RU), Moscow, examined single crystals of elemental antimony (Sb), previously suggested to be a topological material. “It is a good strategy to study interesting physics in a simple system, because that’s where we can hope to understand the fundamental principles,” Sánchez-Barriga explains. “The experimental verification of the topological property of this material required us to directly observe its electronic structure in a highly excited state with time, spin, energy and momentum resolutions, and in this way we accessed an unusual electron dynamics,” adds Sánchez-Barriga.

    Probing the electronic structure

    The aim was to understand how fast excited electrons in the bulk and on the surface of Sb react to the external energy input, and to explore the mechanisms governing their response. “By controlling the time delay between the initial laser excitation and the second pulse that allows us to probe the electronic structure, we were able to build up a full time-resolved picture of how excited states leave and return to equilibrium on ultrafast time scales. The unique combination of time and spin-resolved capabilities also allowed us to directly probe the spin-polarization of excited states far out-of-equilibrium”, says Dr. Oliver J. Clark.

    Weight gain detected

    The data show a “kink” structure in transiently occupied energy-momentum dispersion of surface states, which can be interpreted as an increase in effective electron mass. The authors were able to show that this mass enhancement plays a decisive role in determining the complex interplay in the dynamical behaviors of electrons from the bulk and the surface, also depending on their spin, following the ultrafast optical excitation

    Key to control spin polarised currents

    “Our research reveals which essential properties of this class of materials are the key to systematically control the relevant time scales in which lossless spin-polarised currents could be generated and manipulated,” explains Sánchez-Barriga. These are important steps on the way to spintronic devices which based on topological materials possess advanced functionalities for ultrafast information processing.

    Science paper:
    Communications Physics

    See the full article here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Helmholtz-Zentrum Berlin für Materialien und Energie (Helmholtz Center for Materials and Energy, [HZB]) is part of the Helmholtz Association of German Research Centres [Helmholtz-Gemeinschaft Deutscher Forschungszentren] (DE). The institute studies the structure and dynamics of materials and investigates solar cell technology. It also runs the third-generation BESSY II synchrotron in Adlershof. Until the end of 2019 it ran the 10 megawatt BER II nuclear research reactor at the Lise Meitner campus in Wannsee.

    The Helmholtz-Zentrum Berlin was created on 1 January 2009 by the merger of Hahn-Meitner-Institut Berlin (HMI) and Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY), thus bringing BESSY into the Helmholtz Association.[4]

    The Hahn-Meitner-Institut Berlin (HMI), named after Otto Hahn and Lise Meitner, was founded 14 March 1959 in Berlin-Wannsee to operate the BER I research reactor that began operation with 50 kW on 24 July 1958. Research originally focused on radiochemistry. In 1971, the federal government took over a 90% share in the HMI.

    The Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY) was founded in 1979. The first synchrotron BESSY I in Berlin-Wilmersdorf began operations in 1982.

     
  • richardmitnick 8:34 pm on June 4, 2021 Permalink | Reply
    Tags: "Magnetism Drives Metals to Insulators in New Experiment", , At low temperatures metal conductors act like insulators., , , In 1951 John Slater proposed that as the temperature is lowered an ordered magnetic state would prevent electrons from flowing through material., In some cases it is not easy to predict whether a material is a metal conductor or an insulator., Like all metals silver and copper and gold are conductors., , , Spintronics, These unusual materials go from acting like a chunk of gold to acting like a piece of wood.   

    From California Institute of Technology (US) : “Magnetism Drives Metals to Insulators in New Experiment” 

    Caltech Logo

    From California Institute of Technology (US)

    June 04, 2021

    Whitney Clavin
    (626) 395‑1944
    wclavin@caltech.edu

    Study provides new tools to probe novel spintronic devices

    1
    An illustration of two domains (blue and orange) divided by a domain wall (white area) in a material. The magnetic order is designated with organized arrows (electron spins) while the colors represent two different domains (but the same magnetic order). In the material pictured here, the domain walls are conductive and the domains are insulating. Credit: Yejun Feng.

    2
    Yejun Feng (left), Yishu Wang (right), and Daniel Silevitch (bottom), are pictured here setting up an experiment in the Rosenbaum lab at Caltech.

    Like all metals silver and copper and gold are conductors. Electrons flow across them, carrying heat and electricity. While gold is a good conductor under any conditions, some materials have the property of behaving like metal conductors only if temperatures are high enough; at low temperatures, they act like insulators and do not do a good job of carrying electricity. In other words, these unusual materials go from acting like a chunk of gold to acting like a piece of wood as temperatures are lowered. Physicists have developed theories to explain this so-called metal–insulator transition, but the mechanisms behind the transitions are not always clear.

    “In some cases it is not easy to predict whether a material is a metal or an insulator,” explains Caltech visiting associate Yejun Feng of the Okinawa Institute of Science and Technology Graduate University [沖縄科学技術大学院大学](JP). “Metals are always good conductors no matter what, but some other so-called apparent metals are insulators for reasons that are not well understood.” Feng has puzzled over this question for at least five years; others on his team, such as collaborator David Mandrus at the University of Tennessee (US), have thought about the problem for more than two decades.

    Now, a new study from Feng and colleagues, published in Nature Communications, offers the cleanest experimental proof yet of a metal–insulator transition theory proposed 70 years ago by physicist John Slater. According to that theory, magnetism, which results when the so-called “spins” of electrons in a material are organized in an orderly fashion, can solely drive the metal–insulator transition; in other previous experiments, changes in the lattice structure of a material or electron interactions based on their charges have been deemed responsible.

    “This is a problem that goes back to a theory introduced in 1951, but until now it has been very hard to find an experimental system that actually demonstrates the spin–spin interactions as the driving force because of confounding factors,” explains co-author Thomas Rosenbaum, a professor of physics at Caltech who is also the Institute’s president and the Sonja and William Davidow Presidential Chair.

    “Slater proposed that as the temperature is lowered an ordered magnetic state would prevent electrons from flowing through the material,” Rosenbaum explains. “Although his idea is theoretically sound, it turns out that for the vast majority of materials, the way that electrons interact with each other electronically has a much stronger effect than the magnetic interactions, which made the task of proving the Slater mechanism challenging.”

    The research will help answer fundamental questions about how different materials behave, and may also have applications in technology, for example in the field of spintronics, in which the spins of electrons would form the basis of electrical devices instead of the electron charges as is routine now. “Fundamental questions about metal and insulators will be relevant in the upcoming technological revolution,” says Feng.

    Interacting Neighbors

    Typically, when something is a good conductor, such as a metal, the electrons can zip around largely unimpeded. Conversely, with insulators, the electrons get stuck and cannot travel freely. The situation is comparable to communities of people, explains Feng. If you think of materials as communities and electrons as members of the households, then “insulators are communities with people who don’t want their neighbors to visit because it makes them feel uncomfortable.” Conductive metals, however, represent “close-knit communities, like in a college dorm, where neighbors visit each other freely and frequently,” he says.

    Likewise, Feng uses this metaphor to explain what happens when some metals become insulators as temperatures drop. “It’s like winter time, in that people—or the electrons—stay home and don’t go out and interact.”

    In the 1940s, physicist Sir Nevill Francis Mott figured out how some metals can become insulators. His theory, which garnered the 1977 Nobel Prize in Physics, described how “certain metals can become insulators when the electronic density decreases by separating the atoms from each other in some convenient way,” according to the Nobel Prize press release. In this case, the repulsion between the electrons is behind the transition.

    In 1951, Slater proposed an alternate mechanism based on spin–spin interactions, but this idea has been hard to prove experimentally because the other processes of the metal–insulator transition, including those proposed by Mott, can swamp the Slater mechanism, making it hard to isolate.

    Challenges of Real Materials

    In the new study, the researchers were able at last to experimentally demonstrate the Slater mechanism using a compound that has been studied since 1974, called pyrochlore oxide or Cd2Os2O7. This compound is not affected by other metal–insulator transition mechanisms. However, within this material, the Slater mechanism is overshadowed by an unforeseen experimental challenge, namely the presence of “domain walls” that divide the material into sections.

    “The domain walls are like the highways or bigger roads between communities,” says Feng. In pyrochlore oxide, the domain walls are conductive, even though the bulk of the material is insulating. Although the domain walls started out as an experimental challenge, they turned out to be essential to the team’s development of a new measurement procedure and technique to prove the Slater mechanism.

    “Previous efforts to prove the Slater metal–insulator transition theory did not account for the fact that the domain walls were masking the magnetism-driven effects,” says Yishu Wang (PhD ’18), a co-author at the Johns Hopkins University (US) who has continuously worked on this study since her graduate work at Caltech. “By isolating the domain walls from the bulk of the insulating materials, we were able to develop a more complete understanding of the Slater mechanism.” Wang had previously worked with Patrick Lee, a visiting professor at Caltech from Massachusetts Institute of Technology (US), to lay the basic understanding of conductive domain walls using symmetry arguments, which describe how and if electrons in materials respond to changes in the direction of a magnetic field.

    “By challenging the conventional assumptions about how electrical conductivity measurements are made in magnetic materials through fundamental symmetry arguments, we have developed new tools to probe spintronic devices, many of which depend on transport across domain walls,” says Rosenbaum.

    “We developed a methodology to set apart the domain-wall influence, and only then could the Slater mechanism be revealed,” says Feng. “It’s a bit like discovering a diamond in the rough.”

    The paper was funded by the Okinawa Institute, with subsidy funding from the Cabinet Office, Government of Japan; the National Science Foundation; the Air Force Office of Scientific Research; and the U.S. Department of Energy. Other authors include Daniel M. Silevitch of Caltech and Scott E. Cooper of the Okinawa Institute of Science and Technology. Mandrus is also affiliated with the DOE’s Oak Ridge National Laboratory(US).

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Caltech campus

    The California Institute of Technology (US) is a private research university in Pasadena, California. The university is known for its strength in science and engineering, and is one among a small group of institutes of technology in the United States which is primarily devoted to the instruction of pure and applied sciences.

    Caltech was founded as a preparatory and vocational school by Amos G. Throop in 1891 and began attracting influential scientists such as George Ellery Hale, Arthur Amos Noyes, and Robert Andrews Millikan in the early 20th century. The vocational and preparatory schools were disbanded and spun off in 1910 and the college assumed its present name in 1920. In 1934, Caltech was elected to the Association of American Universities, and the antecedents of National Aeronautics and Space Administration (US)’s Jet Propulsion Laboratory, which Caltech continues to manage and operate, were established between 1936 and 1943 under Theodore von Kármán.

    Caltech has six academic divisions with strong emphasis on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. First-year students are required to live on campus, and 95% of undergraduates remain in the on-campus House System at Caltech. Although Caltech has a strong tradition of practical jokes and pranks, student life is governed by an honor code which allows faculty to assign take-home examinations. The Caltech Beavers compete in 13 intercollegiate sports in the NCAA Division III’s Southern California Intercollegiate Athletic Conference (SCIAC).

    As of October 2020, there are 76 Nobel laureates who have been affiliated with Caltech, including 40 alumni and faculty members (41 prizes, with chemist Linus Pauling being the only individual in history to win two unshared prizes). In addition, 4 Fields Medalists and 6 Turing Award winners have been affiliated with Caltech. There are 8 Crafoord Laureates and 56 non-emeritus faculty members (as well as many emeritus faculty members) who have been elected to one of the United States National Academies. Four Chief Scientists of the U.S. Air Force and 71 have won the United States National Medal of Science or Technology. Numerous faculty members are associated with the Howard Hughes Medical Institute(US) as well as National Aeronautics and Space Administration(US). According to a 2015 Pomona College(US) study, Caltech ranked number one in the U.S. for the percentage of its graduates who go on to earn a PhD.

    Research

    Caltech is classified among “R1: Doctoral Universities – Very High Research Activity”. Caltech was elected to the Association of American Universities in 1934 and remains a research university with “very high” research activity, primarily in STEM fields. The largest federal agencies contributing to research are National Aeronautics and Space Administration(US); National Science Foundation(US); Department of Health and Human Services(US); Department of Defense(US), and Department of Energy(US).

    In 2005, Caltech had 739,000 square feet (68,700 m^2) dedicated to research: 330,000 square feet (30,700 m^2) to physical sciences, 163,000 square feet (15,100 m^2) to engineering, and 160,000 square feet (14,900 m^2) to biological sciences.

    In addition to managing JPL, Caltech also operates the Caltech Palomar Observatory(US); the Owens Valley Radio Observatory(US);the Caltech Submillimeter Observatory(US); the W. M. Keck Observatory at the Mauna Kea Observatory(US); the Laser Interferometer Gravitational-Wave Observatory at Livingston, Louisiana and Richland, Washington; and Kerckhoff Marine Laboratory(US) in Corona del Mar, California. The Institute launched the Kavli Nanoscience Institute at Caltech in 2006; the Keck Institute for Space Studies in 2008; and is also the current home for the Einstein Papers Project. The Spitzer Science Center(US), part of the Infrared Processing and Analysis Center(US) located on the Caltech campus, is the data analysis and community support center for NASA’s Spitzer Infrared Space Telescope [no longer in service].

    Caltech partnered with University of California at Los Angeles(US) to establish a Joint Center for Translational Medicine (UCLA-Caltech JCTM), which conducts experimental research into clinical applications, including the diagnosis and treatment of diseases such as cancer.

    Caltech operates several Total Carbon Column Observing Network(US) stations as part of an international collaborative effort of measuring greenhouse gases globally. One station is on campus.

     
  • richardmitnick 12:06 pm on April 18, 2021 Permalink | Reply
    Tags: , “Spin” is a property of particles like electrons in the same way that “charge” is., Fabry-Perot device, If you use spin waves it's transfer of spin- you don't move charge so you don't create heating., , , Spin waves can be used to do computing in ways that are faster that electronic computing at specific tasks., Spintronics, Using spintronics to make computer chips and devices for data processing and communication technology that are small and powerful.   

    From Aalto University [Aalto-yliopisto] (FI): “New nanoscale device for spin technology” 

    From Aalto University [Aalto-yliopisto] (FI)

    16.4.2021

    Prof. Sebastiaan van Dijken
    sebastiaan.van.dijken@aalto.fi
    +358-50-3160969

    Dr Huajun Qin
    E-mail: huajun.qin@aalto.fi

    Spin waves could unlock the next generation of computer technology, a new component allows physicists to control them.

    1
    Magneto-optical microscope used for imaging spin waves in a Fabry-Pérot resonator.

    2
    A commercial Fabry-Perot device. Credit: Christophe.Finot

    4
    Fabry–Pérot interferometer, using a pair of partially reflective, slightly wedged optical flats. The wedge angle is highly exaggerated in this illustration; only a fraction of a degree is actually necessary to avoid ghost fringes. Low-finesse versus high-finesse images correspond to mirror reflectivities of 4% (bare glass) and 95%. Credit: User:Stigmatella aurantiaca.

    Researchers at Aalto University [ Aalto-yliopisto](FI) have developed a new device for spintronics. The results have been published in the journal Nature Communications, and mark a step towards the goal of using spintronics to make computer chips and devices for data processing and communication technology that are small and powerful.

    Traditional electronics uses electrical charge to carry out computations that power most of our day-to-day technology. However, engineers are unable to make electronics do calculations faster, as moving charge creates heat, and we’re at the limits of how small and fast chips can get before overheating. Because electronics can’t be made smaller, there are concerns that computers won’t be able to get more powerful and cheaper at the same rate they have been for the past 7 decades. This is where spintronics comes in.

    “Spin” is a property of particles like electrons in the same way that “charge” is. Researchers are excited about using spin to carry out computations because it avoids the heating issues of current computer chips. ‘If you use spin waves it’s transfer of spin- you don’t move charge so you don’t create heating,’ says Professor Sebastiaan van Dijken, who leads the group that wrote the paper.

    Nanoscale magnetic materials

    The device the team made is a Fabry-Pérot resonator, a well known tool in optics for creating beams of light with a tightly controlled wavelength. The spin-wave version made by the researchers in this work allows them to control and filter waves of spin in devices that are only a few hundreds of nanometres across.

    The devices were made by sandwiching very thin layers of materials with exotic magnetic properties on top of each other. This created a device where the spin waves in the material would be trapped and cancelled out if they weren’t of the desired frequency. ‘The concept is new, but easy to implement,’ explains Dr Huajun Qin, the first author of the paper, ‘the trick is to make good quality materials, which we have here at Aalto. The fact that it is not challenging to make these devices means we have lots of opportunities for new exciting work.’

    Wireless data processing and analogue computing

    The issues with speeding up electronics goes beyond overheating, they also cause complications in wireless transmission, as wireless signals need to be converted from their higher frequencies down to frequencies that electronic circuits can manage. This conversion slows the process down, and requires energy. Spin wave chips are able to operate at the microwave frequencies used in mobile phone and wifi signals, which means that there is a lot of potential for them to be used in even faster and more reliable wireless communication technologies in the future.

    Furthermore, spin waves can be used to do computing in ways that are faster that electronic computing at specific tasks. ‘Electronic computing uses “Boolean” or Binary logic to do calculations,’ explains Professor van Dijken, ‘with spin waves, the information is carried in the amplitude of the wave, which allows for more analogue style computing. This means that it could be very useful for specific tasks like image processing, or pattern recognition. The great thing about our system is that the size structure of it means that it should be easy to integrate into existing technology’

    Now that the team has the resonator to filter and control the spin waves, the next steps are to make a complete circuit for them. “To build a magnetic circuit, we need to be able to guide the spin waves towards functional components, like the way conducting electrical channels do on electronic microchips. We are looking at making similar structures to steer spin waves” explains Dr Qin.

    See the full article here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Aalto University [Aalto-yliopisto] (FI) is a university located in Espoo, Finland. It was established in 2010 as a merger of three major Finnish universities: the Helsinki University of Technology (established 1849), the Helsinki School of Economics (established 1904), and the University of Art and Design Helsinki (established 1871). The close collaboration between the scientific, business and arts communities is intended to foster multi-disciplinary education and research. The Finnish government, in 2010, set out to create a university that fosters innovation, merging the three institutions into one.

    The university is composed of six schools with close to 17,500 students and 4,000 staff members, making it Finland’s second largest university. The main campus of Aalto University is located in Otaniemi, Espoo. Aalto University Executive Education operates in the district of Töölö, Helsinki. In addition to the Greater Helsinki area, the university also operates its Bachelor’s Programme in International Business in Mikkeli and the Metsähovi Radio Observatory in Kirkkonummi.

    Aalto University’s operations showcase Finland’s experiment in higher education. The Aalto Design Factory, Aalto Ventures Program and Aalto Entrepreneurship Society (Aaltoes), among others, drive the university’s mission for a radical shift towards multidisciplinary learning and have contributed substantially to the emergence of Helsinki as a hotbed for startups. Aaltoes is Europe’s largest and most active student run entrepreneurship community that has founded major concepts such as the Startup Sauna accelerator program and the Slush startup event.

    The university is named in honour of Alvar Aalto, a prominent Finnish architect, designer and alumnus of the former Helsinki University of Technology, who was also instrumental in designing a large part of the university’s main campus in Otaniemi.

     
  • richardmitnick 9:44 pm on February 9, 2021 Permalink | Reply
    Tags: A Monte Carlo simulation technique, , D-Wave processors are now being used to simulate magnetic systems of practical interest., , , Fractional magnetization plateaus, Magnetic structure, , Quantum annealing-a form of quantum computing, , Quantum Science Center-a DOE Quantum Information Science Research Center established at ORNL in 2020., , Shastry-Sutherland Ising model, Spintronics, Their novel simulations will serve as a foundation to streamline future efforts on next-generation quantum computers.   

    From DOE’s Oak Ridge National Laboratory: “Quantum computing enables simulations to unravel mysteries of magnetic materials” 

    From DOE’s Oak Ridge National Laboratory

    February 9, 2021
    Scott S Jones
    jonesg@ornl.gov
    865.241.6491

    1
    The researchers embedded a programmable model into a D-Wave quantum computer chip. Credit: D-Wave.

    A multi-institutional team became the first to generate accurate results from materials science simulations on a quantum computer that can be verified with neutron scattering experiments and other practical techniques.

    Researchers from the Department of Energy’s Oak Ridge National Laboratory; the University of Tennessee, Knoxville; Purdue University and D-Wave Systems harnessed the power of quantum annealing, a form of quantum computing, by embedding an existing model into a quantum computer.

    Characterizing materials has long been a hallmark of classical supercomputers, which encode information using a binary system of bits that are each assigned a value of either 0 or 1. But quantum computers — in this case, D-Wave’s 2000Q – rely on qubits, which can be valued at 0, 1 or both simultaneously because of a quantum mechanical capability known as superposition.

    “The underlying method behind solving materials science problems on quantum computers had already been developed, but it was all theoretical,” said Paul Kairys, a student at UT Knoxville’s Bredesen Center for Interdisciplinary Research and Graduate Education who led ORNL’s contributions to the project. “We developed new solutions to enable materials simulations on real-world quantum devices.”

    This unique approach proved that quantum resources are capable of studying the magnetic structure and properties of these materials, which could lead to a better understanding of spin liquids, spin ices and other novel phases of matter useful for data storage and spintronics applications. The researchers published the results of their simulations — which matched theoretical predictions and strongly resembled experimental data — in PRX Quantum.

    Eventually, the power and robustness of quantum computers could enable these systems to outperform their classical counterparts in terms of both accuracy and complexity, providing precise answers to materials science questions instead of approximations. However, quantum hardware limitations previously made such studies difficult or impossible to complete.

    To overcome these limitations, the researchers programmed various parameters into the Shastry-Sutherland Ising model. Because it shares striking similarities with the rare earth tetraborides, a class of magnetic materials, subsequent simulations using this model could provide substantial insights into the behavior of these tangible substances.

    “We are encouraged that the novel quantum annealing platform can directly help us understand materials with complicated magnetic phases, even those that have multiple defects,” said co-corresponding author Arnab Banerjee, an assistant professor at Purdue. “This capability will help us make sense of real material data from a variety of neutron scattering, magnetic susceptibility and heat capacity experiments, which can be very difficult otherwise.”

    2
    Using the D-Wave chip (foreground), the team simulated the experimental signature of a sample material(background), producing results that are directly comparable to the output from real-world experiments. Credit: Paul Kairys/UT Knoxville.

    Magnetic materials can be described in terms of magnetic particles called spins. Each spin has a preferred orientation based on the behavior of its neighboring spins, but rare earth tetraborides are frustrated, meaning these orientations are incompatible with each other. As a result, the spins are forced to compromise on a collective configuration, leading to exotic behavior such as fractional magnetization plateaus. This peculiar behavior occurs when an applied magnetic field, which normally causes all spins to point in one direction, affects only some spins in the usual way while others point in the opposite direction instead.

    Using a Monte Carlo simulation technique powered by the quantum evolution of the Ising model, the team evaluated this phenomenon in microscopic detail.

    “We came up with new ways to represent the boundaries, or edges, of the material to trick the quantum computer into thinking that the material was effectively infinite, and that turned out to be crucial for correctly answering materials science questions,” said co-corresponding author Travis Humble. Humble is an ORNL researcher and deputy director of the Quantum Science Center, or QSC, a DOE Quantum Information Science Research Center established at ORNL in 2020. The individuals and institutions involved in this research are QSC members.

    Quantum resources have previously simulated small molecules to examine chemical or material systems. Yet, studying magnetic materials that contain thousands of atoms is possible because of the size and versatility of D-Wave’s quantum device.

    “D-Wave processors are now being used to simulate magnetic systems of practical interest, resembling real compounds. This is a big deal and takes us from the notepad to the lab,” said Andrew King, director of performance research at D-Wave. “The ultimate goal is to study phenomena that are intractable for classical computing and outside the reach of known experimental methods.”

    The researchers anticipate that their novel simulations will serve as a foundation to streamline future efforts on next-generation quantum computers. In the meantime, they plan to conduct related research through the QSC, from testing different models and materials to performing experimental measurements to validate the results.

    “We completed the largest simulation possible for this model on the largest quantum computer available at the time, and the results demonstrated the significant promise of using these techniques for materials science studies going forward,” Kairys said.

    This work was funded by the DOE Office of Science Early Career Research Program. Access to the D-Wave 2000Q system was provided through the Quantum Computing User Program managed by the Oak Ridge Leadership Computing Facility, a DOE Office of Science user facility located at ORNL.

    Research performed at ORNL’s Spallation Neutron Source, also a DOE Office of Science user facility located at ORNL, was supported by the DOE Office of Science.

    ORNL Spallation Neutron Source.


    ORNL Spallation Neutron Source annotated.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science. DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.

    i2

     
  • richardmitnick 12:33 pm on February 1, 2021 Permalink | Reply
    Tags: "Unlocking the power of a molecule’s spin", , , New research provides a theoretical framework that could help experimentalists better control chemical reactions with possible implications for recycling rare earth metals., One of the properties of a metal is that it has certain spin properties., , , Rare earth metals- a group of 17 elements that because they aren’t found in concentrated deposits require energy-intensive and toxic methods to extract., Spintronics, Theoretical chemistry   

    From Penn Today: “Unlocking the power of a molecule’s spin” 


    From Penn Today

    January 29, 2021
    Erica K. Brockmeier

    New research provides a theoretical framework that could help experimentalists better control chemical reactions, with possible implications for recycling rare earth metals.

    1
    A new study led by Joseph Subotnik (right) describes a theoretical framework that could allow experimentalists to have better control over chemical reactions by using a molecule’s spin. Using this framework, future experiments conducted through the Center for Sustainable Separations of Metals (CSSM) with Eric Schelter (far left) and Jessica Anna could help researchers develop more energy-efficient ways to purify and recycle scarce materials such as rare earth metals. (Pre-pandemic image). Credit: Eric Sucar.

    3
    Toward Control of Spin States for Molecular Electronics. Credit: ALS LBNL.

    Behind the devices that shape modern life is an array of natural and human-made materials. One such component of smartphones and computers are rare earth metals, a group of 17 elements that, because they aren’t found in concentrated deposits, require energy-intensive and toxic methods to extract. While recycling rare earth metals from used devices is one way to relieve strained supply chains and reduce environmental damage, the fundamental chemistry required for efficiently separating and reusing these metals remains a challenge.

    Now, new research provides a theoretical framework that could change the paradigm for how chemicals are separated. Graduate student Yanze Wu and professor Joseph Subotnik describe in Nature Communications how a molecule’s spin can be used to control a chemical reaction. Based on this concept, future experiments conducted through the Center for Sustainable Separations of Metals (CSSM) could help researchers develop more energy-efficient ways to purify and recycle scarce materials such as rare earth metals.

    The goal of the CSSM, established in 2019 and led by a team of Penn chemists, is to develop chemical separation methods that make the process of recycling metals from consumer products more cost-effective. CSSM brings together theoretical and experimental chemistry groups, with the goal of conducting fundamental research that provides creative, scientifically-driven solutions to the rare earth metal supply chain crisis.

    Subotnik, a theoretical chemist, had previously been working on questions related to photochemistry and was interested in understanding how light impacts molecules. In the process of trying to better understand the dynamics of photochemical reactions, he and Wu began to postulate the role of spin during light-induced changes to a molecule’s energy state. After spending a year delving deeply into this area of study, Subotnik realized through conversations with CSSM Director Eric Schelter that this theoretical work could also have implications for metal separation.

    “One of the reasons rare earth metal separation is hard is because a lot of metals are very similar to each other. But one of the properties of a metal is that it has certain spin properties,” Subotnik says. “One idea is that if you want to separate metals, you might be able to use spin properties, which can be very different.”

    2
    To help validate their findings, Subotnik will be working with Schelter and Anna to conduct follow-up experiments and combine those data with new theoretical models. (Pre-pandemic image). Credit: Eric Sucar.

    In this new theoretical framework, the researchers show that spin helps molecules as they pass through unstable geometries during a chemical reaction. Subotnik uses the analogy of finding a secret mountain pass and how controlling spin could enable someone to travel to a specific place, in this case a particular product of a chemical reaction, on the other side. “We show that a little bit of spin can force you to take one pass versus the other with a huge fidelity, and just a little bit of spin can guide which product you’re going to make,” he says.

    What’s significant about this idea is that a molecule’s spin can be changed using a very small amounts of energy, and this small change in spin also has enormous effects on how a chemical reaction proceeds. While using spin to power devices has been the ambition of fields like spintronics, its implications in fundamental chemistry have not been widely explored. “The question is, Can you use these really small energies to make nonintuitive chemistry happen,” says Subotnik. “If I understand spin and can manipulate it, could I promote one reaction or the other, to get one metal to separate rather than another?”

    But what makes this discovery exciting also makes the next steps challenging: “It’s powerful, but it’s hard to diagnose,” Subotnik says. Because a molecule’s spin rotates with the molecule itself and averages out during experiments, it’s difficult to isolate spin’s impacts in lab measurements. To help validate their findings, Subotnik will be working with Schelter and Jessica Anna to conduct follow-up experiments and combine those data with new theoretical models.

    “The recent announcements by the Biden administration and General Motors for a wholesale shift to electric vehicles will create huge demands for mining lithium, cobalt, rare earths, and other critical metals,” says Schelter, “Joe and Yanze’s work has important implications for fundamentally new and selective separations of critical metals that could reduce energy consumption, waste, and greenhouse gas production associated with mining, or enable critical metals recycling.”

    Beyond its implications for metal separation, this framework also paves the way for a new paradigm on how electrical, spin, and other chemical properties could be combined in ways that have not been explored before. “Nobody’s really combined these aspects of spin and chemistry before, so I do’’t know what’s going to happen,” Subotnik says. “The dream would be that you make some process way more efficient. That’s fundamental science at its best.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Penn campus

    Academic life at Penn is unparalleled, with 100 countries and every U.S. state represented in one of the Ivy League’s most diverse student bodies. Consistently ranked among the top 10 universities in the country, Penn enrolls 10,000 undergraduate students and welcomes an additional 10,000 students to our world-renowned graduate and professional schools.

    Penn’s award-winning educators and scholars encourage students to pursue inquiry and discovery, follow their passions, and address the world’s most challenging problems through an interdisciplinary approach.

     
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