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  • richardmitnick 9:16 pm on June 30, 2022 Permalink | Reply
    Tags: "BerkSEL": Berkeley Surface Emitting Laser, "New single-mode semiconductor laser delivers power with scalability", A semiconductor membrane perforated with evenly spaced and same-sized holes functioned as a perfect scalable laser cavity., , Berkeley engineers have created a new type of semiconductor laser that meets an elusive goal in optics: the ability to emit a single mode of light with the ability to scale up in size and power., , , Laser Technology, , , , Scanning electron micrography, , The laser emits a consistent single wavelength regardless of the size of the cavity., The membrane in the study had about 3000 holes but theoretically it could have been 1 million or 1 billon holes., The study’s results are particularly relevant to vertical-cavity surface-emitting lasers [VCSELs], This new laser capability enables lasers to be more powerful and to cover longer distances for many applications.   

    From Berkeley Engineering: “New single-mode semiconductor laser delivers power with scalability” 

    From Berkeley Engineering

    At

    The University of California-Berkeley

    June 29, 2022
    Sarah Yang

    1
    Schematic of the Berkeley Surface Emitting Laser (BerkSEL) illustrating the pump beam (blue) and the lasing beam (red). The unconventional design of the semiconductor membrane synchronizes all unit-cells (or resonators) in phase so that they are all participating in the lasing mode. (Image courtesy of the Kanté group)

    Berkeley engineers have created a new type of semiconductor laser that accomplishes an elusive goal in the field of optics: the ability to emit a single mode of light while maintaining the ability to scale up in size and power. It is an achievement that means size does not have to come at the expense of coherence, enabling lasers to be more powerful and to cover longer distances for many applications.

    A research team led by Boubacar Kanté, Chenming Hu Associate Professor in UC Berkeley’s Department of Electrical Engineering and Computer Sciences (EECS) and faculty scientist at the Materials Sciences Division of the DOE’s Lawrence Berkeley National Laboratory, showed that a semiconductor membrane perforated with evenly spaced and same-sized holes functioned as a perfect scalable laser cavity. They demonstrated that the laser emits a consistent single wavelength regardless of the size of the cavity.

    2
    Top view of a scanning electron micrograph of the Berkeley Surface Emitting Laser (BerkSEL). The hexagonal lattice photonic crystal (PhC) forms an electromagnetic cavity. (Image courtesy of the Kanté group)

    The researchers described their invention, dubbed Berkeley Surface Emitting Lasers (BerkSELs), in a study published June 29, 2022 in the journal Nature.

    “Increasing both size and power of a single-mode laser has been a challenge in optics since the first laser was built in 1960,” said Kanté. “Six decades later, we show that it is possible to achieve both these qualities in a laser. I consider this the most important paper my group has published to date.”

    Despite the vast array of applications ushered in by the invention of the laser — from surgical tools to barcode scanners to precision etching — there has been a persistent limit that researchers in optics have had to contend with. The coherent, single-wavelength directional light that is a defining characteristic of a laser starts to break down as the size of the laser cavity increases. The standard workaround is to use external mechanisms, such as a waveguide, to amplify the beam.

    “Using another medium to amplify laser light takes up a lot of space,” said Kanté. “By eliminating the need for external amplification, we can shrink the size and increase the efficiency of computer chips and other components that rely upon lasers.”

    The study’s results are particularly relevant to vertical-cavity surface-emitting lasers, or VCSELs, in which laser light is emitted vertically out of the chip. Such lasers are used in a wide range of applications, including fiber optic communications, computer mice, laser printers and biometric identification systems.

    VCSELs are typically tiny, measuring a few microns wide. The current strategy used to boost their power is to cluster hundreds of individual VCSELs together. Because the lasers are independent, their phase and wavelength differ, so their power does not combine coherently.

    “This can be tolerated for applications like facial recognition, but it’s not acceptable when precision is critical, like in communications or for surgery,” said study co-lead author Rushin Contractor, an EECS Ph.D. student.

    Kanté compares the extra efficiency and power enabled by BerkSEL’s single-mode lasing to a crowd of people getting a stalled bus to move. Multi-mode lasing is akin to people pushing in different directions, he said. It would not only be less effective, but it could also be counterproductive if people are pushing in opposite directions. Single-mode lasing in BerkSELs is comparable to each person in the crowd pushing the bus in the same direction. This is far more efficient than what is done in existing lasers where, using the same analogy, only part of the crowd contributes to pushing the bus.

    3
    Schematic showing the “Dirac cones.” Light is emitted synchronously from the entire semiconductor cavity as a result of the Dirac point singularity. (Image courtesy of the Kanté group)

    The study found that the BerkSEL design enabled the single-mode light emission because of the physics of the light passing through the holes in the membrane, a 200-nanometer-thick layer of indium gallium arsenide phosphide, a semiconductor commonly used in fiber optics and telecommunications technology. The holes, which were etched using lithography, had to be a fixed size, shape and distance apart.

    The researchers explained that the periodic holes in the membrane became Dirac points, a topological feature of two-dimensional materials based on the linear dispersion of energy. They are named after English physicist and Nobel laureate Paul Dirac, known for his early contributions to quantum mechanics and quantum electrodynamics.

    The researchers point out that the phase of light that propagates from one point to the other is equal to the refractive index multiplied by the distance traveled. Because the refractive index is zero at the Dirac point, light emitted from different parts of the semiconductor are exactly in phase and thus optically the same.

    “The membrane in our study had about 3000 holes but theoretically it could have been 1 million or 1 billon holes, and the result would have been the same,” said study co-lead author, Walid Redjem, an EECS postdoctoral researcher.

    The researchers used a high-energy pulsed laser to optically pump and provide energy to the BerkSEL devices. They measured the emission from each aperture using a confocal microscope optimized for near-infrared spectroscopy.

    The semiconductor material and the dimensions of the structure used in this study were selected to enable lasing at telecommunications wavelength. Authors noted that BerkSELs can emit different target wavelengths by adapting the design specifications, such as hole size and semiconductor material.

    Other study authors are Wanwoo Noh, co-lead author who earned his Ph.D. degree in EECS in May 2022; Wayesh Qarony, Scott Dhuey and Adam Schwartzberg from Berkeley Lab; and Emma Martin, a Ph.D. student in EECS.

    The Office of Naval Research provided the primary support for this study. Additional funding came from the National Science Foundation, the Berkeley Lab, the Moore Inventor Fellows program and UC Berkeley’s Bakar Fellowship.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The College of Engineering, also known informally as Berkeley Engineering or CoE, is one of the fourteen schools and colleges at the University of California, Berkeley. Established in 1931, the college is considered among the most prestigious engineering schools in the world, ranked third by U.S. News & World Report and with an acceptance rate of 8%. Berkeley Engineering is particularly well known for producing many successful entrepreneurs; among its alumni are co-founders and CEOs of some of the largest companies in the world, including Apple, Boeing, Google, Intel, and Tesla.

    The college is currently situated in 14 buildings on the northeast side of the central campus, and also operates at the 150 acre (61 ha) Richmond Field Station. With the Haas School of Business, the college confers joint degrees and advises the university’s resident startup incubator, Berkeley SkyDeck.

    Departments

    Aerospace Engineering
    Bioengineering (BioE)
    Civil and Environmental Engineering (CEE)
    Development Engineering (DevEng)
    Electrical Engineering and Computer Sciences (EECS)
    Engineering Science
    Energy Engineering
    Engineering Mathematics and Statistics (EMS)
    Engineering Physics
    Environmental Engineering Science (EES)
    Industrial Engineering and Operations Research (IEOR)
    Materials Science and Engineering (MSE)
    Mechanical Engineering (ME)
    Nuclear Engineering (NE)

    The College of Letters and Science also offers a Bachelor of Arts in computer science, which requires many of the same courses as the College of Engineering’s Bachelor of Science in EECS, but has different admissions and graduation criteria. Berkeley’s chemical engineering department is under the College of Chemistry.

    Research units

    All research facilities are managed by one of five Organized Research Units (ORUs):

    Earthquake Engineering Research Center – research and public safety programs against the destructive effects of earthquakes
    Electronics Research Laboratory – the largest ORU; advanced research in novel areas within seven different university departments, organized into five main divisions:
    Berkeley Sensor & Actuator Center
    Berkeley Wireless Research Center
    Berkeley Northside Research Group
    Micro Systems Group
    Engineering Systems Research Center – focuses on manufacturing, mechatronics, and microelectro mechanical systems (MEMS)
    Institute for Environmental Science and Engineering – focuses on applying basic research to current and future environmental problems
    Institute of Transportation Studies – sponsors research in transportation planning, policy analysis, environmental concerns and transportation system performance

    Major research centers and programs

    Jacobs Institute for Design Innovation
    Berkeley Institute of Design
    Berkeley Multimedia Research Center
    Center for Information Technology Research in the Interest of Society (CITRIS)
    Center for Intelligent Systems – developing a unified theoretical foundation for intelligent systems.
    Consortium on Green Design and Manufacturing
    Digital Library Project
    UCSF/Berkeley Ergonomics Program
    International Computer Science Institute – basic research institute focusing on Internet architecture, speech and language processing, artificial intelligence, and cognitive and theoretical computer science
    Intel Research Laboratory @ Berkeley
    Integrated Materials Laboratory – facilities for research in nano-structure growth, processing, and characterization
    Microfabrication Laboratory
    The Millennium Project – developing a hierarchical campus-wide “cluster of clusters” to support advanced computational applications
    Nokia Research Center @ Berkeley
    Pacific Earthquake Engineering Research Center
    Partners for Advanced Transit & Highways – researching ways to improve the operation of California’s state highway system
    Power Systems Engineering Research Center

    The The University of California-Berkeley 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 system and a founding member of the Association of American Universities . 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, DOE’s Lawrence Livermore National Laboratory and DOE’s Los Alamos National Lab, 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 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, University of California-San Fransisco, 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 among US universities; five Turing Awards, behind only MIT and Stanford University; 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

     
  • richardmitnick 4:00 pm on June 20, 2022 Permalink | Reply
    Tags: "Excitons": Quasiparticles that can transport energy while remaining electrically neutral., "LAST": Laser-assisted synthesis technique, "Physicists Shine Light on Solid Way To Extend Excitons’ Life", "TMDs": Two-dimensional transition metal dichalcogenides, , , Excitons in LAST-produced TMDs lasted up to 100 times longer than those in other TMD materials., it creates a negatively charged electron paired with a positive hole to maintain neutral charge. This pair is the exciton., Laser Technology, , , , , , Semiconductors are a class of crystalline solids whose electrical conductivity is between that of a conductor and an insulator., Strain-controlling in atomically thin monolayer of TMDs is an important tool to tailor their optoelectronic properties., The indirect excitons can be both electronically controlled and converted into photons opening a path to the development of new optoelectronic devices., The indirect excitons exist due to the abnormal amount of strain between the monolayer TMD material and the substrate on which it grows., The pair still have a Coulomb interaction between them., , Ultrafast Spectroscopy, When a semiconductor absorbs a photon   

    From The University of Texas-Dallas : “Physicists Shine Light on Solid Way To Extend Excitons’ Life” 

    From The University of Texas-Dallas

    June 17, 2022
    Stephen Fontenot,
    UT Dallas,
    972-883-4405
    stephen.fontenot@utdallas.edu,

    1
    Dr. Anton Malko’s Optics and Ultrafast Spectroscopy Laboratory focuses on the science and engineering of excitonic processes in various novel nanomaterials and hybrid structures. Malko and fellow researchers tested ultrathin semiconductors made with a method called laser-assisted synthesis technique in a recent study.

    Optics researchers at The University of Texas at Dallas have shown for the first time that a new method for manufacturing ultrathin semiconductors yields material in which excitons survive up to 100 times longer than in materials created with previous methods.

    The findings show that excitons, quasiparticles that transport energy, last long enough for a broad range of potential applications, including as bits in quantum computing devices.

    Dr. Anton Malko, professor of physics in the School of Natural Sciences and Mathematics, is corresponding author of a paper published online March 30 in Advanced Materials that describes tests on ultrathin semiconductors made with a recently developed method called laser-assisted synthesis technique (LAST). The findings show novel quantum physics at work.

    Semiconductors are a class of crystalline solids whose electrical conductivity is between that of a conductor and an insulator. This conductivity can be externally controlled, either by doping or electrical gating, making them key elements for the diodes and transistors that underpin all modern electronic technology.

    Two-dimensional transition metal dichalcogenides (TMDs) are a novel type of ultrathin semiconductor consisting of a transition metal and a chalcogen element arranged in one atomic layer. While TMDs have been explored for a decade or so, the 2D form that Malko examined has advantages in scalability and optoelectronic properties.

    “LAST is a very pure method. You take pure molybdenum or tungsten, and pure selenium or sulfur, and evaporate them under intense laser light,” Malko said. “Those atoms are distributed onto a substrate and make the two-dimensional TMD layer less than 1 nanometer thick.”

    A material’s optical properties are partially determined by the behavior of excitons, which are quasiparticles that can transport energy while remaining electrically neutral.

    “When a semiconductor absorbs a photon, it creates in the semiconductor a negatively charged electron paired with a positive hole, to maintain neutral charge. This pair is the exciton. The two parts are not completely free from each other — they still have a Coulomb interaction between them,” Malko said.

    Malko and his team were surprised to discover that excitons in LAST-produced TMDs lasted up to 100 times longer than those in other TMD materials.

    “We quickly found that, optically speaking, these 2D samples behave totally differently from any we’ve seen in 10 years working with TMDs,” he said. “When we started to look deeper at it, we realized it’s not a fluke; it’s repeatable and dependent on growth conditions.”

    These longer lifetimes, Malko believes, are caused by indirect excitons, which are optically inactive.

    “These excitons are used as a kind of reservoir to slowly feed the optically active excitons,” he said.

    Lead study author Dr. Navendu Mondal, a former UT Dallas postdoctoral researcher who is now a Marie Skłodowska-Curie Individual Fellow at Imperial College London, said he believes the indirect excitons exist due to the abnormal amount of strain between the monolayer TMD material and the substrate on which it grows.

    “Strain-controlling in atomically thin monolayer of TMDs is an important tool to tailor their optoelectronic properties,” Mondal said. “Their electronic band-structure is highly sensitive to structural deformations. Under enough strain, band-gap modifications cause formation of various indirect ‘dark’ excitons that are optically inactive. Through this finding, we reveal how the presence of these hidden dark excitons influences those excitons created directly by photons.”

    Malko said the built-in strain in 2D TMDs is comparable to what would be induced by pressing on the material with externally placed micro- or nanosize pillars, although it is not a viable technological option for such thin layers.

    “That strain is crucial for creating these optically inactive, indirect excitons,” he said. “If you remove the substrate, the strain is released, and this wonderful optical response is gone.”

    Malko said the indirect excitons can be both electronically controlled and converted into photons opening a path to the development of new optoelectronic devices.

    “This increased lifespan has very interesting potential applications,” he said. “When an exciton has a lifespan of only about 100 picoseconds or less, there is no time to use it. But in this material, we can create a reservoir of inactive excitons that live much longer — a few nanoseconds instead of hundreds of picoseconds. You can do a lot with this.”

    Malko said the results of the research are an important proof-of-concept for future quantum-scale devices.

    “It’s the first time we know of that anyone has made this fundamental observation of such long-living excitations in TMD materials — long enough to be usable as a quantum bit — just like an electron in a transistor or even just for light harvesting in a solar cell,” he said. “Nothing in the literature can explain these superlong exciton lifetimes, but we now understand why they have these characteristics.”

    The researchers next will try to manipulate excitons with an electric field, which is a key step toward creating quantum-level logic elements.

    “Classical semiconductors have already been miniaturized down to the doorstep before quantum effects change the game entirely,” Malko said. “If you can apply gate voltage and show that 2D TMD materials will work for future electronic devices, it’s a huge step. The atomic monolayer in 2D TMD material is 10 times smaller than the size limit with silicon. But can you create logic elements at that size? That’s what we need to find out.”

    Other key contributors to this research are Dr. Yuri Gartstein, associate professor of physics at UT Dallas who did computational modeling that explained the reservoir behavior and coupling between different exciton species; and Dr. Masoud Mahjouri-Samani and graduate student Nurul Azam from Auburn University, who developed and used the LAST method to create the semiconductor material.

    Funding for the research came from the U.S. Department of Energy, Basic Energy Sciences program (BES award #DE-SC0010697).

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Texas at Dallas is a Carnegie R1 classification (Doctoral Universities – Highest research activity) institution, located in a suburban setting 20 miles north of downtown Dallas. The University enrolls more than 27,600 students — 18,380 undergraduate and 9,250 graduate —and offers a broad array of bachelor’s, master’s, and doctoral degree programs.

    Established by Eugene McDermott, J. Erik Jonsson and Cecil Green, the founders of Texas Instruments, UT Dallas is a young institution driven by the entrepreneurial spirit of its founders and their commitment to academic excellence. In 1969, the public research institution joined The University of Texas System and became The University of Texas at Dallas.

    A high-energy, nimble, innovative institution, UT Dallas offers top-ranked science, engineering and business programs and has gained prominence for a breadth of educational paths from audiology to arts and technology. UT Dallas’ faculty includes a Nobel laureate, six members of the National Academies and more than 560 tenured and tenure-track professors.

     
  • richardmitnick 7:49 am on June 18, 2022 Permalink | Reply
    Tags: "BEC" is the fifth state of matter., "BEC":Bose-Einstein condensate, "One Step Closer to Continuous-Wave Atom Lasers", , Laser Technology, , , The laser light used to cool atoms and create the condensate also quickly destroys it., To create a steady flow of BEC to fuel a continuous-wave atom laser the scientists spread the laser cooling of strontium atoms not over time but rather through space.   

    From Optics & Photonics : “One Step Closer to Continuous-Wave Atom Lasers” 

    From Optics & Photonics

    6.16.22
    Sarah Michaud

    1
    The central part of the Bose-Einstein condensate (BEC) demonstration in which coherent matter waves are created. New strontium atoms (blue) fall in and make their way to the BEC in the center. This image has been altered; in reality, the atoms are not visible to the naked eye. [Image: UvA/Image processing by Scixel]

    Physicists based in the Netherlands designed and demonstrated a method for producing ultracold particles that could be used to provide a steady and sustainable flow of Bose-Einstein condensate (BEC) for an atom laser. A continuous-wave atom laser, analogous to a continuous-wave optical laser, would produce a coherent beam of matter instead of light (Nature).

    The team’s new cooling method chills strontium atoms to almost absolute zero by moving them through consecutive cooling steps instead of gradually cooling the atoms over time in one place. Not only does this increase the chances of the atoms condensing into a coherent wave, but it also works as a sort-of BEC conveyer belt that could, in theory, be used to indefinitely power an atom laser.

    The trouble with Bose-Einstein condensate

    The key component of an atom laser is BEC, the fifth state of matter. BEC forms when a very diffuse gas is cooled, usually with lasers and evaporative cooling, to nearly absolute zero (about -273 °C). At this ultracold temperature, the atoms collectively fall into the lowest quantum state, condense into a coherent wave, and form BEC. This BEC can be extracted by an output coupler device to produce a beam of matter, much like coherent photons in a beam of laser light.

    Unfortunately, the laser light used to cool atoms and create the condensate also quickly destroys it, thus limiting atom-laser output to very short pulses. To create a continuous-wave atom laser, the University of Amsterdam’s Florian Schreck and his team figured out a way to create a steady supply of BEC.

    Replenishing BEC and future directions

    To create a steady flow of BEC to fuel a continuous-wave atom laser, Schreck and his colleagues spread the laser cooling of strontium atoms not over time, but rather through space. “We make the atoms move while they progress through consecutive cooling steps,” Schreck explained in a press release. “In the end, ultracold atoms arrive at the heart of the experiment, where they can be used to form coherent matter waves in a BEC.” As the atoms are used and destroyed, a whole reservoir of newly cooling atoms is waiting right behind them to replenish the BEC.

    The experimental setup to demonstrate the team’s method started with a stream of strontium atoms that was loaded into a crossed-beam dipole trap. The trap formed a reservoir where the atoms were laser-cooled. A “transparency” laser beam was applied to the reservoir, creating a light shift that made the strontium atoms transparent to the damaging light from the cooling lasers. The cooled atoms condensed into an ultracold gas dimple at the bottom of the reservoir and formed the BEC.

    The physicists used atomic cloud density images to confirm that their technique did indeed create a continuous flow of BEC. They further validated these results by fitting the images to theoretical distributions. The team’s next steps include increasing BEC purity by enhancing the phase-space flux loading the dimple and lowering the reservoir temperature with Raman cooling.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Optics and Photonics News (OPN) is The Optical Society’s monthly news magazine. It provides in-depth coverage of recent developments in the field of optics and offers busy professionals the tools they need to succeed in the optics industry, as well as informative pieces on a variety of topics such as science and society, education, technology and business. OPN strives to make the various facets of this diverse field accessible to researchers, engineers, businesspeople and students. Contributors include scientists and journalists who specialize in the field of optics. We welcome your submissions.

     
  • richardmitnick 9:05 pm on June 15, 2022 Permalink | Reply
    Tags: "What quantum information and snowflakes have in common and what we can do about it", A network would link up dozens or even hundreds of quantum chips., A team of physicists demonstrated that it could read out the signals from a type of qubit called a superconducting qubit using laser light—and without destroying the qubit at the same time., , Companies like IBM and Google [Alphabet] have begun designing quantum computer chips using qubits made from superconductors., Electro-optic transducer, Even the tiniest disturbance can collapse that superposition., , Laser Technology, Lasers are the nemesis of superconducting qubits., , , , , , Qubits through a property called “superposition” can exist as zeros and ones at the same time., Solving problems that are beyond the reach of even the fastest supercomputers around today., The researchers say the group’s results could be a major step toward building a quantum internet.,   

    From The University of Colorado-Boulder: “What quantum information and snowflakes have in common and what we can do about it” 

    U Colorado

    From The University of Colorado-Boulder

    June 15, 2022
    Daniel Strain

    Qubits are a basic building block for quantum computers, but they’re also notoriously fragile—tricky to observe without erasing their information in the process. Now, new research from CU Boulder and the National Institute of Standards and Technology may be a leap forward for handling qubits with a light touch.

    In the study, a team of physicists demonstrated that it could read out the signals from a type of qubit called a superconducting qubit using laser light—and without destroying the qubit at the same time.

    1
    Artist’s depiction of an electro-optic transducer, an ultra-thin device that can capture and transform the signals coming from a superconducting qubit. (Credit: Steven Burrows/JILA)

    The group’s results could be a major step toward building a quantum internet, the researchers say. Such a network would link up dozens or even hundreds of quantum chips, allowing engineers to solve problems that are beyond the reach of even the fastest supercomputers around today. They could also, theoretically, use a similar set of tools to send unbreakable codes over long distances.

    The study, published June 15 in the journal Nature, was led by JILA [Joint Institute for Laboratory Astrophysics], a joint research institute between CU Boulder and NIST.

    “Currently, there’s no way to send quantum signals between distant superconducting processors like we send signals between two classical computers,” said Robert Delaney, lead author of the study and a former graduate student at JILA.

    Quantum computers, which run on qubits, get their power by tapping into the properties of quantum physics, or the physics governing very small things. Delaney explained the traditional bits that run your laptop are pretty limited: They can only take on a value of zero or one, the numbers that underly most computer programming to date. Qubits, in contrast, can be zeros, ones or, through a property called “superposition,” exist as zeros and ones at the same time.

    But working with qubits is also a bit like trying to catch a snowflake in your warm hand. Even the tiniest disturbance can collapse that superposition, causing them to look like normal bits.

    In the new study, Delaney and his colleagues showed they could get around that fragility. The team uses a wafer-thin piece of silicon and nitrogen to transform the signal coming out of a superconducting qubit into visible light—the same sort of light that already carries digital signals from city to city through fiberoptic cables.

    “Researchers have done experiments to extract optical light from a qubit, but not disrupting the qubit in the process is a challenge,” said study co-author Cindy Regal, JILA fellow and associate professor of physics at CU Boulder.

    Fragile qubits

    There are a lot of different ways to make a qubit, she added.

    Some scientists have assembled qubits by trapping an atom in laser light. Others have experimented with embedding qubits into diamonds and other crystals. Companies like IBM and Google have begun designing quantum computer chips using qubits made from superconductors.

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    A quantum computer chip designed by IBM that includes four superconducting qubits. (Credit: npj Quantum Information, 2017)

    Superconductors are materials that electrons can speed around without resistance. Under the right circumstances, superconductors will emit quantum signals in the form of tiny particles of light, or “photons,” that oscillate at microwave frequencies.

    And that’s where the problem starts, Delaney said.

    To send those kinds of quantum signals over long distances, researchers would first need to convert microwave photons into visible light, or optical, photons—which can whiz in relative safety through networks fiberoptic cables across town or even between cities. But when it comes to quantum computers, achieving that transformation is tricky, said study co-author Konrad Lehnert.

    In part, that’s because one of the main tools you need to turn microwave photons into optical photons is laser light, and lasers are the nemesis of superconducting qubits. If even one stray photon from a laser beam hits your qubit, it will erase completely.

    “The fragility of qubits and the essential incompatibility between superconductors and laser light makes usually prevents this kind of readout,” said Lehnert, a NIST and JILA fellow.

    Secret codes

    To get around that obstacle, the team turned to a go-between: a thin piece of material called an electro-optic transducer.

    Delaney explained the team begins by zapping that wafer, which is too small to see without a microscope, with laser light. When microwave photons from a qubit bump into the device, it wobbles and spits out more photons—but these ones now oscillate at a completely different frequency. Microwave light goes in, and visible light comes out

    In the latest study, the researchers tested their transducer using a real superconducting qubit. They discovered the thin material could achieve this switcheroo while also effectively keeping those mortal enemies, qubits and lasers, isolated from each other. In other words, none of the photons from the laser light leaked back to disrupt the superconductor.

    “Our electro-optic transducer does not have much effect on the qubit,” Delaney said.

    The team hasn’t gotten to the point where it can transmit actual quantum information through its microscopic telephone booth. Among other issues, the device isn’t particularly efficient yet. It takes about 500 microwave photons, on average, to produce a single visible light photon.

    The researchers are currently working to improve that rate. Once they do, new possibilities may emerge in the quantum realm. Scientists could, theoretically, use a similar set of tools to send quantum signals over cables that would automatically erase their information when someone was trying to listen in. Mission Impossible made real, in other words, and all thanks to the sensitive qubit.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Colorado Campus

    As the flagship university of the state of Colorado The University of Colorado-Boulder , founded in 1876, five months before Colorado became a state. It is a dynamic community of scholars and learners situated on one of the most spectacular college campuses in the country, and is classified as an R1 University, meaning that it engages in a very high level of research activity. As one of 34 U.S. public institutions belonging to the prestigious Association of American Universities ), a selective group of major research universities in North America, – and the only member in the Rocky Mountain region – we have a proud tradition of academic excellence, with five Nobel laureates and more than 50 members of prestigious academic academies.

    University of Colorado-Boulder has blossomed in size and quality since we opened our doors in 1877 – attracting superb faculty, staff, and students and building strong programs in the sciences, engineering, business, law, arts, humanities, education, music, and many other disciplines.

    Today, with our sights set on becoming the standard for the great comprehensive public research universities of the new century, we strive to serve the people of Colorado and to engage with the world through excellence in our teaching, research, creative work, and service.

    In 2015, the university comprised nine colleges and schools and offered over 150 academic programs and enrolled almost 17,000 students. Five Nobel Laureates, nine MacArthur Fellows, and 20 astronauts have been affiliated with CU Boulder as students; researchers; or faculty members in its history. In 2010, the university received nearly $454 million in sponsored research to fund programs like the Laboratory for Atmospheric and Space Physics and JILA. CU Boulder has been called a Public Ivy, a group of publicly funded universities considered as providing a quality of education comparable to those of the Ivy League.

    The Colorado Buffaloes compete in 17 varsity sports and are members of the NCAA Division I Pac-12 Conference. The Buffaloes have won 28 national championships: 20 in skiing, seven total in men’s and women’s cross country, and one in football. The university has produced a total of ten Olympic medalists. Approximately 900 students participate in 34 intercollegiate club sports annually as well.

    On March 14, 1876, the Colorado territorial legislature passed an amendment to the state constitution that provided money for the establishment of the University of Colorado in Boulder, the Colorado School of Mines in Golden, and the Colorado State University – College of Agricultural Sciences in Fort Collins.

    Two cities competed for the site of the University of Colorado: Boulder and Cañon City. The consolation prize for the losing city was to be home of the new Colorado State Prison. Cañon City was at a disadvantage as it was already the home of the Colorado Territorial Prison. (There are now six prisons in the Cañon City area.)

    The cornerstone of the building that became Old Main was laid on September 20, 1875. The doors of the university opened on September 5, 1877. At the time, there were few high schools in the state that could adequately prepare students for university work, so in addition to the University, a preparatory school was formed on campus. In the fall of 1877, the student body consisted of 15 students in the college proper and 50 students in the preparatory school. There were 38 men and 27 women, and their ages ranged from 12–23 years.

    During World War II, Colorado 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.

    University of Colorado-Boulder hired its first female professor, Mary Rippon, in 1878. It hired its first African-American professor, Charles H. Nilon, in 1956, and its first African-American librarian, Mildred Nilon, in 1962. Its first African American female graduate, Lucile Berkeley Buchanan, received her degree in 1918.

    Research institutes

    University of Colorado-Boulder’s research mission is supported by eleven research institutes within the university. Each research institute supports faculty from multiple academic departments, allowing institutes to conduct truly multidisciplinary research.

    The Institute for Behavioral Genetics (IBG) is a research institute within the Graduate School dedicated to conducting and facilitating research on the genetic and environmental bases of individual differences in behavior. After its founding in 1967 IBG led the resurging interest in genetic influences on behavior. IBG was the first post-World War II research institute dedicated to research in behavioral genetics. IBG remains one of the top research facilities for research in behavioral genetics, including human behavioral genetics, psychiatric genetics, quantitative genetics, statistical genetics, and animal behavioral genetics.

    The Institute of Cognitive Science (ICS) at CU Boulder promotes interdisciplinary research and training in cognitive science. ICS is highly interdisciplinary; its research focuses on education, language processing, emotion, and higher level cognition using experimental methods. It is home to a state-of-the-art fMRI system used to collect neuroimaging data.

    ATLAS Institute is a center for interdisciplinary research and academic study, where engineering, computer science and robotics are blended with design-oriented topics. Part of CU Boulder’s College of Engineering and Applied Science, the institute offers academic programs at the undergraduate, master’s and doctoral levels, and administers research labs, hacker and makerspaces, and a black box experimental performance studio. At the beginning of the 2018–2019 academic year, approximately 1,200 students were enrolled in ATLAS academic programs and the institute sponsored six research labs.[64]

    In addition to IBG, ICS and ATLAS, the university’s other institutes include Biofrontiers Institute, Cooperative Institute for Research in Environmental Sciences, Institute of Arctic & Alpine Research (INSTAAR), Institute of Behavioral Science (IBS), JILA, Laboratory for Atmospheric & Space Physics (LASP), Renewable & Sustainable Energy Institute (RASEI), and the University of Colorado Museum of Natural History.

     
  • richardmitnick 12:34 pm on June 13, 2022 Permalink | Reply
    Tags: , A superradiant burst can indicate collective behavior among arrays of atoms., Any atom array is capable of bursting—a sign that atoms are syncing up., , Laser Technology, , , This approach overcomes a big problem in quantum physics., When atoms interact with each other they behave as a whole rather than individual entities.   

    From The Columbia Quantum Initiative: “Columbia Physicists Shine New Light on an Old Quantum Optics Problem About Collective Behavior” 

    1

    3

    From The Columbia Quantum Initiative

    at

    Columbia U bloc

    Columbia University

    May 18, 2022 [JUst now in social media.]
    Ellen Neff

    Calculations from Ana Asenjo-Garcia and Stuart Masson reveal that any atom array is capable of bursting—a sign that atoms are syncing up.

    1
    Light burst. Credit: Gerd Altmann from Pixabay.

    When atoms interact with each other they behave as a whole rather than individual entities. That can give rise to synchronized responses to inputs, a phenomenon that, if properly understood and controlled, may prove useful for developing light sources, building sensors that can take ultraprecise measurements, and understanding dissipation in quantum computers.

    But can you tell when atoms in a group are synced up? In new work in Nature Communications, Columbia physicist Ana Asenjo-Garcia and her postdoc Stuart Masson show how a phenomenon called a superradiant burst can indicate collective behavior among arrays of atoms, solving what’s been a decades-old problem for the field of quantum optics.

    Shining a laser on an atom adds energy, putting it into what’s known as an “excited” state. Eventually it will decay back to its baseline energy level, releasing the extra energy in the form of a particle of light called a photon. Back in the 1950s, physicist Robert Dicke showed that the intensity of the light pulse emitted from a single excited atom, which emits photons at random times, will immediately start to decline. The pulse from a group will actually be “superradiant,” with intensity increasing at first because the atoms emit most of the energy in a short, bright burst of light.

    The problem? In Dicke’s theory, the atoms are all contained within a single point—a theoretical possibility that can’t exist in reality.

    For decades, researchers debated whether atoms spaced out into different arrangements, like lines or simple grids, would exhibit superradiance, or if any distance would immediately eliminate this outward sign of collective behavior. According to Masson and Asenjo-Garcia’s calculations, the potential is always there. “No matter how you arrange your atoms or how many there are, there will always be a superradiant burst if they are close enough together,” Masson said.

    Their approach overcomes a big problem in quantum physics: as a system gets bigger, it becomes exponentially more complicated to perform calculations about it. According to Asenjo-Garcia and Masson’s work, predicting superradiance all comes down to just two photons. If the first photon emitted from the group does not speed up the emission of the second, a burst will not ensue. The determining factor is the distance between atoms, which varies by how they are arranged. For example, an array of 40×40 atoms will exhibit a burst if they are within 0.8 of a wavelength of one another.

    According to Masson, that’s an achievable distance in state-of-the-art experimental set ups. Though it can’t yet fill in details about the strength or duration of the burst if the array is larger than 16 atoms (those precise calculations are too complicated, even on Columbia’s supercomputers), the simple predictive framework Masson and Asenjo-Garcia developed can indicate whether a given experimental array will produce superradiance, which is a sign that atoms are behaving collectively.

    In some applications—for example, in so-called superradiant lasers, which are less sensitive to thermal fluctuations than conventional ones—synchronized atoms are a desirable feature that researchers will want to incorporate into their devices. In other applications, such as attempts to physically shrink atomic arrays for quantum computing, collective behavior could cause unintended outcomes if not properly accounted for. “You can’t escape the collective nature of atoms, and it can occur at distances larger than you might expect,” said Masson.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    In the first half of the 20th century, the first quantum revolution gave us a new way of thinking about the way the world works and brought us technologies such as lasers, MRI machines, and the transistors that underpin all aspects of modern life. Today, the second quantum revolution is underway, and it’s all about control.
    The coming generation of quantum technologies will be built on new physical principles and demand new materials, new methods of investigation, and new collaborations. At Columbia, we’re tackling these demands together and training the next generation of quantum scientists and entrepreneurs.
    Building on the collaborative culture long fostered at Columbia, the Columbia Quantum Initiative is combining interdisciplinary expertise in materials science, photonics, quantum theory, and more, all while taking advantage of our unique position in the global hub that is New York to develop novel quantum technologies that will open new frontiers into how we compute through complex problems, communicate with one another, and sense the world around us.

    Columbia U Campus
    Columbia University was founded in 1754 as King’s College by royal charter of King George II of England. It is the oldest institution of higher learning in the state of New York and the fifth oldest in the United States.

    University Mission Statement

    Columbia University is one of the world’s most important centers of research and at the same time a distinctive and distinguished learning environment for undergraduates and graduate students in many scholarly and professional fields. The University recognizes the importance of its location in New York City and seeks to link its research and teaching to the vast resources of a great metropolis. It seeks to attract a diverse and international faculty and student body, to support research and teaching on global issues, and to create academic relationships with many countries and regions. It expects all areas of the University to advance knowledge and learning at the highest level and to convey the products of its efforts to the world.

    Columbia University is a private Ivy League research university in New York City. Established in 1754 on the grounds of Trinity Church in Manhattan Columbia is the oldest institution of higher education in New York and the fifth-oldest institution of higher learning in the United States. It is one of nine colonial colleges founded prior to the Declaration of Independence, seven of which belong to the Ivy League. Columbia is ranked among the top universities in the world by major education publications.

    Columbia was established as King’s College by royal charter from King George II of Great Britain in reaction to the founding of Princeton College. It was renamed Columbia College in 1784 following the American Revolution, and in 1787 was placed under a private board of trustees headed by former students Alexander Hamilton and John Jay. In 1896, the campus was moved to its current location in Morningside Heights and renamed Columbia University.

    Columbia scientists and scholars have played an important role in scientific breakthroughs including brain-computer interface; the laser and maser; nuclear magnetic resonance; the first nuclear pile; the first nuclear fission reaction in the Americas; the first evidence for plate tectonics and continental drift; and much of the initial research and planning for the Manhattan Project during World War II. Columbia is organized into twenty schools, including four undergraduate schools and 15 graduate schools. The university’s research efforts include The Lamont–Doherty Earth Observatory, The Goddard Institute for Space Studies, and accelerator laboratories with major technology firms such as IBM. Columbia is a founding member of the The Association of American Universities and was the first school in the United States to grant the M.D. degree. With over 14 million volumes, Columbia University Library is the third largest private research library in the United States.
    The university’s endowment stands at $11.26 billion in 2020, among the largest of any academic institution. As of October 2020, Columbia’s alumni, faculty, and staff have included: five Founding Fathers of the United States—among them a co-author of the United States Constitution and a co-author of the Declaration of Independence; three U.S. presidents; 29 foreign heads of state; ten justices of the United States Supreme Court, one of whom currently serves; 96 Nobel laureates; five Fields Medalists; 122 National Academy of Sciences members; 53 living billionaires; eleven Olympic medalists; 33 Academy Award winners; and 125 Pulitzer Prize recipients.

     
  • richardmitnick 10:31 pm on June 8, 2022 Permalink | Reply
    Tags: "Uncovering a novel way to bring to Earth the energy that powers the sun and stars", , , , Laser Technology, , , Tungsten boosts the performance of the implosions that cause fusion reactions in the pellets.   

    From The DOE’s Princeton Plasma Physics Laboratory: “Uncovering a novel way to bring to Earth the energy that powers the sun and stars” 

    From The DOE’s Princeton Plasma Physics Laboratory

    at

    Princeton University

    Princeton University

    June 8, 2022
    Raphael Rosen

    1
    From left: PPPL physicists Ken Hill, Lan Gao, and Brian Kraus; image of the National Ignition Facility (Collage courtesy of Kiran Sudarsanan)

    Scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have uncovered critical new details about fusion facilities that use lasers to compress the fuel that produces fusion energy. The new data could help lead to the improved design of future laser facilities that harness the fusion process that drives the sun and stars.

    Fusion combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.

    Major experimental facilities include tokamaks, the magnetic fusion devices that PPPL studies; stellarators, the magnetic fusion machines that PPPL also studies and have recently become more widespread around the world; and laser devices used in what are called inertial confinement experiments.

    The researchers explored the impact of adding tungsten metal, which is used to make cutting tools and lamp filaments, to the outer layer of plasma fuel pellets in inertial confinement research. They found that tungsten boosts the performance of the implosions that cause fusion reactions in the pellets. The tungsten helps block heat that would prematurely raise the temperature at the center of the pellet.

    The research team confirmed the findings by making measurements using krypton gas, sometimes used in fluorescent lamps. Once added to the fuel, the gas emitted high-energy light known as X-rays that was captured by an instrument called a high-resolution X-ray spectrometer. The X-rays conveyed clues about what was happening inside the capsule.

    “I was excited to see that we could make these unprecedented measurements using the technique we have been developing these past few years. This information helps us evaluate the pellet’s implosion and helps researchers calibrate their computer simulations,” said PPPL physicist Lan Gao, lead author of the paper reporting the results in Physical Review Letters. “Better simulations and theoretical understanding in general can help researchers design better future experiments.”

    The scientists performed the experiments at the National Ignition Facility (NIF), a DOE user facility at Lawrence Livermore National Laboratory.

    The facility shines 192 lasers onto a gold cylinder, or hohlraum, that is one centimeter tall and encases the fuel. The laser beams heat the hohlraum, which radiates X-rays evenly onto the fuel pellet within.

    “It’s like an X-ray bath,” said PPPL physicist Brian Kraus, who contributed to the research. “That’s why it’s good to use a hohlraum. You could shine lasers directly onto the fuel pellet, but it’s difficult to get even coverage.”

    Researchers want to understand how the pellet is compressed so they can design future facilities to make the heating more efficient. But getting information about the pellet’s interior is difficult. “Since the material is very dense, almost nothing can get out,” Kraus said. “We want to measure the inside, but it’s hard to find something that can go through the fuel pellet’s shell.”

    “The results presented in Lan’s paper are of great importance to inertial fusion and provided a new method of characterizing burning plasmas,” said Phil Efthimion, head of the Plasma Science & Technology Department at PPPL and leader of the collaboration with NIF.

    The researchers used a PPPL-designed high-resolution X-ray spectrometer to collect and measure the radiated X-rays with more detail than had been measured before. By analyzing how the X-rays changed every 25 trillionth of a second, the team was able to track how the plasma changed over time.

    “Based on that information, we could estimate the size and density of the pellet core more precisely than before, helping us determine the efficiency of the fusion process,” Gao said. “We provided direct evidence that adding tungsten increases both density and temperature and therefore pressure in the compressed pellet. As a result, fusion yield increases.”

    “We are looking forward to collaborating with theoretical, computational, and experimental teams to take this research further,” she said.

    The research team included collaborators from Lawrence Livermore National Laboratory, the Laboratory for Laser Energetics at the University of Rochester, the Massachusetts Institute of Technology (MIT), and Israel’s Weizmann Institute of Science. This research was supported by the DOE’s Office of Science (Fusion Energy Sciences).

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    The Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single 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. For more information, please visit https://energy.gov/science.

     
  • richardmitnick 9:12 pm on June 8, 2022 Permalink | Reply
    Tags: "Axial Higgs mode"-a magnetic relative of the mass-defining Higgs Boson particle, "Axial Higgs mode:: Elusive particle discovered in a material through tabletop experiment", , , , Boston College, Laser Technology, , The team focused on RTe3-or rare-earth tritelluride-a well-studied quantum material that can be examined at room temperature in a "tabletop" experimental format.   

    From Boston College via “phys.org” : “Axial Higgs mode:: Elusive particle discovered in a material through tabletop experiment” 

    From Boston College

    via

    “phys.org”

    June 8, 2022

    1
    An interdisciplinary team led by Boston College physicists has discovered a new particle – or a previously undetectable quantum excitation – known as the axial Higgs mode, a magnetic relative of the mass-defining Higgs Boson particle, the team reports in the journal Nature. Credit: Nature (2022).

    An interdisciplinary team led by Boston College physicists has discovered a new particle—or previously undetectable quantum excitation—known as the axial Higgs mode-a magnetic relative of the mass-defining Higgs Boson particle, the team reports in the online edition of the journal Nature.

    The detection a decade ago of the long-sought Higgs Boson became central to the understanding of mass.

    Unlike its parent, axial Higgs mode has a magnetic moment, and that requires a more complex form of the theory to explain its properties, said Boston College Professor of Physics Kenneth Burch, a lead co-author of the report Axial Higgs Mode Detected by Quantum Pathway Interference in RTe3.

    Theories that predicted the existence of such a mode have been invoked to explain “dark matter,” the nearly invisible material that makes up much of the universe, but only reveals itself via gravity, Burch said.

    Whereas Higgs Boson was revealed by experiments in a massive particle collider, the team focused on RTe3, or rare-earth tritelluride, a well-studied quantum material that can be examined at room temperature in a “tabletop” experimental format.

    “It’s not every day you find a new particle sitting on your tabletop,” Burch said.

    RTe3 has properties that mimic the theory that produces the axial Higgs mode, Burch said. But the central challenge in finding Higgs particles in general is their weak coupling to experimental probes, such as beams of light, he said. Similarly, revealing the subtle quantum properties of particles usually requires rather complex experimental setups including enormous magnets and high-powered lasers, while cooling samples to extremely cold temperatures.

    The team reports that it overcame these challenges through the unique use of the scattering of light and proper choice of quantum simulator, essentially a material mimicking the desired properties for study.

    Specifically, the researchers focused on a compound long known to possess a “charge density wave,” namely a state where electrons self-organize with a density that is periodic in space, Burch said.

    The fundamental theory of this wave mimics components of the standard model of particle physics, he added. However, in this case, the charge density wave is quite special, it emerges far above room temperature and involves modulation of both the charge density and the atomic orbits. This allows for the Higgs Boson associated with this charge density wave to have additional components, namely it could be axial, meaning it contains angular momentum.

    In order to reveal the subtle nature of this mode, Burch explained that the team used light scattering, where a laser is shined on the material and can change color as well as polarization. The change in color results from the light creating the Higgs Boson in the material, while the polarization is sensitive to the symmetry components of the particle.

    In addition, through proper choice of the incident and outgoing polarization, the particle could be created with different components—such as one absent magnetism, or a component pointing up. Exploiting a fundamental aspect of quantum mechanics, they used the fact that for one configuration, these components cancel. However, for a different configuration they add.

    “As such, we were able to reveal the hidden magnetic component and prove the discovery of the first axial Higgs mode,” Burch said.

    “The detection of the axial Higgs was predicted in high-energy particle physics to explain dark matter,” Burch said. “However, it has never been observed. Its appearance in a condensed matter system was completely surprising and heralds the discovery of a new broken symmetry state that had not been predicted. Unlike the extreme conditions typically required to observe new particles, this was done at room temperature in a table top experiment where we achieve quantum control of the mode by just changing the polarization of light.”

    Burch said the seemingly accessible and straightforward experimental techniques deployed by the team can be applied to study in other areas.

    “Many of these experiments were performed by an undergraduate in my lab,” Burch said. “The approach can be straightforwardly applied to the quantum properties of numerous collective phenomena including modes in superconductors, magnets, ferroelectrics, and charge density waves. Furthermore, we bring the study of quantum interference in materials with correlated and/or topological phases to room temperature overcoming the difficulty of extreme experimental conditions.”

    In addition to Burch, Boston College co-authors on the report included undergraduate student Grant McNamara, recent doctoral graduate Yiping Wang, and post-doctoral researcher Md Mofazzel Hosen. Wang won the Best Dissertation in Magnetism from the American Physical Society, in part for her work on the project, Burch said.

    Burch said it was crucial to draw on the broad range of expertise among researchers from BC, Harvard University, Princeton University, the University of Massachusetts-Amherst, Yale University, University of Washington, and the Chinese Academy of Sciences.

    “This shows the power of interdisciplinary efforts in revealing and controlling new phenomena,” Burch said. “It’s not every day you get optics, chemistry, physical theory, materials science and physics together in one work.”

    See the full article here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Boston College is a private, Jesuit research university in Chestnut Hill, Massachusetts. Founded in 1863, the university has more than 9,300 full-time undergraduates and nearly 5,000 graduate students. Although Boston College is classified as an R1 research university, it still uses the word “college” in its name to reflect its historical position as a small liberal arts college. Its main campus is a historic district and features some of the earliest examples of collegiate gothic architecture in North America.

    Boston College offers bachelor’s degrees, master’s degrees, and doctoral degrees through its eight colleges and schools: Morrissey College of Arts & Sciences, Carroll School of Management, Lynch School of Education and Human Development, Connell School of Nursing, Graduate School of Social Work, Boston College Law School, Boston College School of Theology and Ministry, Woods College of Advancing Studies.

    Boston College athletic teams are the Eagles. Their colors are maroon and gold and their and mascot is Baldwin the Eagle. The Eagles compete in NCAA Division I as members of the Atlantic Coast Conference in all sports offered by the ACC. The men’s and women’s ice hockey teams compete in Hockey East. Boston College’s men’s ice hockey team has won five national championships.

    Alumni and affiliates of the university include governors, ambassadors, members of Congress, scholars, writers, medical researchers, Hollywood actors, and professional athletes. Boston College has graduated several Rhodes, Fulbright, and Goldwater scholars. Other notable alumni include a U.S. Speaker of the House, a U.S. Secretary of State, and chief executives of Fortune 500 companies.

    Schools and colleges

    As a research university, Boston College is made up of a total of eight constituent colleges and schools:[48]

    Morrissey College of Arts & Sciences
    Carroll School of Management
    Lynch School of Education and Human Development
    Connell School of Nursing
    Boston College School of Social Work
    Boston College Law School
    Boston College School of Theology and Ministry
    Woods College of Advancing Studies

    Research centers and institutes

    Boisi Center for Religion and American Public Life
    Business Institute
    Center for Asset Management
    Center for Child, Family, and Community Partnerships (CCFCP)
    Center for Christian-Jewish Learning
    Center for Corporate Citizenship (CCC)
    Center for East Europe, Russia, and Asia
    Center for Human Rights and International Justice
    Center for Ignatian Spirituality
    Center for International Higher Education
    Center for Investment and Research Management
    Center for Irish Programs Dublin
    Center for Nursing Research
    Center for Retirement Research
    Center for the Study of Home and Community Life
    Center for Study of Testing, Evaluation, and Educational Policy (CSTEEP)
    Center for Work and Family (CWF)
    Center on Aging & Work – Workplace Flexibility
    Center on Wealth and Philanthropy (CWP, formerly SWRI)
    Church in the 21st Century Center
    Clough Center for the Study of Constitutional Democracy
    EagleEyes Project
    Institute for Medieval Philosophy and Theology
    Institute of Religious Education and Pastoral Ministry (IREPM)
    Institute for Administrators in Catholic Higher Education
    Institute for Scientific Research
    Institute for the Study and Promotion of Race and Culture (ISPRC)
    International Study Center
    Irish Institute
    Jesuit Institute
    Lifelong Learning Institute
    Lonergan Institute
    Mathematics Institute
    Media Research and Action Project
    Presidential Scholars Program
    Sloan Work and Family Research Network
    Small Business Development Center
    Urban Ecology Institute
    Weston Observatory
    Winston Center for Leadership and Ethics
    Women’s Resource Center

     
  • richardmitnick 9:23 pm on June 6, 2022 Permalink | Reply
    Tags: , A new method to measure structures of light called ‘eigenmodes’., Another step forward in detecting and analyzing the information carried by gravitational waves., , , Laser Technology, Looking for the small ‘wiggles’ in power that can limit the detectors’ sensitivity., Probing the interiors of neutron stars and testing fundamental limits of General Relativity., Solving the mode sensing problem in future gravitational wave detectors is essential if we are to understand the insides of neutron stars.,   

    From The ARC Centres of Excellence for Gravitational Wave Discovery – OzGrav (AU): “New laser breakthrough to help understanding of gravitational waves” 

    arc-centers-of-excellence-bloc

    From The ARC Centres of Excellence for Gravitational Wave Discovery – OzGrav (AU)

    6.7.22
    MILKA BUKILICIN – UWA RESEARCH

    1
    A schematic of the apparatus used by the researchers. ‘f’ is the focal length of the lens.

    Gravitational wave scientists from The University of Western Australia have led the development of a new laser modesensor with unprecedented precision that will be used to probe the interiors of neutron stars and test fundamental limits of general relativity.

    Research Associate from UWA’s Centre of Excellence for Gravitational Wave Discovery (OzGrav-UWA) Dr Aaron Jones,said UWA co-ordinated a global collaboration of gravitational wave, metasurface and photonics experts to pioneer a new method to measure structures of light called ‘eigenmodes’.

    “Gravitational wave detectors like LIGO, Virgo and KAGRA store enormous amount of optical power and several pairs of mirrors are used to increase the amount of laser light stored along the massive arms of the detector,” Dr Jones said.

    ___________________________________________________________________
    LIGOVIRGOKAGRA

    Caltech /MIT Advanced aLigo.

    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA.

    Caltech/MIT Advanced aLigo Hanford, WA, USA installation.

    VIRGO Gravitational Wave interferometer, near Pisa, Italy.

    KAGRA Large-scale Cryogenic Gravitational Wave Telescope Project (JP).
    ___________________________________________________________________

    LIGO Virgo Kagra Masses in the Stellar Graveyard. Credit: Frank Elavsky and Aaron Geller at Northwestern University.
    ___________________________________________________________________

    “However, each of these pairs has small distortions that scatters light away from the perfect shape of the laser beam which can cause excess noise in the detector, limiting sensitivity and taking the detector offline.

    “We wanted to test an idea that would let us zoom in on the laser beam and look for the small ‘wiggles’ in power that can limit the detectors’ sensitivity.”

    Dr Jones said a similar problem is encountered in the telecoms industry where scientists are investigating ways to use multiple eigenmodes to transport more data down optical fibres.

    “Telecoms scientists have developed a way to measure the eigenmodes using a simple apparatus, but it’s not sensitive enough for our purposes,” he said. “We had the idea to use a metasurface – an ultra-thin surface with a special patternencoded in sub-wavelength size – and reached out to collaborators who could help us make one.”

    The proof-of-concept setup the team developed was over one thousand times more sensitive than the original apparatus developed by telecoms scientists and the researchers will now look to translate this work into gravitational-wave detectors.

    OzGrav-UWA Chief Investigator Associate Professor Chunnong Zhao said the development is another step forward in detecting and analyzing the information carried by gravitational waves, allowing us to observe the universe in new ways.

    “Solving the mode sensing problem in future gravitational wave detectors is essential if we are to understand the insides of neutron stars and further our observation of the universe in a way never before possible,” Associate ProfessorZhao said.

    The breakthrough is detailed in a study published in Physical Review.

    See the full article here .

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    OzGrav (AU)


    The ARC Centres of Excellence for Gravitational Wave Discovery OzGrav (AU)
    A new window of discovery.
    A new age of gravitational wave astronomy.
    One hundred years ago, Albert Einstein produced one of the greatest intellectual achievements in physics, the theory of general relativity. In general relativity, spacetime is dynamic. It can be warped into a black hole. Accelerating masses create ripples in spacetime known as gravitational waves (GWs) that carry energy away from the source. Recent advances in detector sensitivity led to the first direct detection of gravitational waves in 2015. This was a landmark achievement in human discovery and heralded the birth of the new field of gravitational wave astronomy. This was followed in 2017 by the first observations of the collision of two neutron-stars. The accompanying explosion was subsequently seen in follow-up observations by telescopes across the globe, and ushered in a new era of multi-messenger astronomy.

    The mission of The ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) is to capitalise on the historic first detections of gravitational waves to understand the extreme physics of black holes and warped spacetime, and to inspire the next generation of Australian scientists and engineers through this new window on the Universe.

    OzGrav is funded by the Australian Government through the Australian Research Council Centres of Excellence funding scheme, and is a partnership between Swinburne University of Technology (AU) (host of OzGrav headquarters), the Australian National University (AU), Monash University (AU), University of Adelaide (AU), University of Melbourne (AU), and University of Western Australia (AU), along with other collaborating organisations in Australia and overseas.
    ________________________________________________________

    The objectives for the The ARC Centres of Excellence are to:

    undertake highly innovative and potentially transformational research that aims to achieve international standing in the fields of research envisaged and leads to a significant advancement of capabilities and knowledge

    link existing Australian research strengths and build critical mass with new capacity for interdisciplinary, collaborative approaches to address the most challenging and significant research problems

    develope relationships and build new networks with major national and international centres and research programs to help strengthen research, achieve global competitiveness and gain recognition for Australian research

    build Australia’s human capacity in a range of research areas by attracting and retaining, from within Australia and abroad, researchers of high international standing as well as the most promising research students

    provide high-quality postgraduate and postdoctoral training environments for the next generation of researchers

    offer Australian researchers opportunities to work on large-scale problems over long periods of time

    establish Centres that have an impact on the wider community through interaction with higher education institutes, governments, industry and the private and non-profit sector.

     
  • richardmitnick 3:40 pm on June 6, 2022 Permalink | Reply
    Tags: , Laser Technology, , , "Adapting a Surface Microscopy Tool for Quantum Studies", "TEMs": transmission electron microscopes, "SEMs": scanning electron microscopes, SEMs can map the elemental composition of rocks right out of the ground., "IELS": inelastic electron-light scattering, Imaging with IELS is called "photon-induced near-field electron microscopy" (PINEM)., PINEM has imaged the optical properties of systems such as surface plasmons and nanoparticles; proteins and cells and even chiral nanostructures.   

    From “physicsworld.com” : “Adapting a Surface Microscopy Tool for Quantum Studies” 

    From “physicsworld.com”

    Tyler Harvey | Lawrence Berkeley National Laboratory

    Scanning electron microscopes using laser-engineered electron quantum states enter the quantum optics ring.

    1
    An ultraviolet laser pulse (purple) triggers photoemission of an electron pulse (green) from the scanning electron microscope’s electron source. These electrons are focused onto the specimen—for this instrument, possibilities include just-fabricated metamaterials, in situ retinal implants, or two-level quantum systems such as a quantum dot—where they interact with the optical field of a second infrared laser pulse (red). This interaction can prepare electrons into a superposition of energy states separated exactly by the infrared photon energy, as recorded by a spectrometer. The lower right inset shows electron energy spectra with increasing interaction strength along the vertical axis.

    Often, the best way to understand the structure and behavior of a material is to examine it under a microscope. To reveal features on a scale smaller than the wavelength of visible light—about 1/100th the width of human hair—electrons are often the right tool for the job. Researchers have used transmission electron microscopes (TEMs) to image the motion of single atoms and the structure of SARS-CoV-2, the virus that causes COVID-19. Scanning electron microscopes (SEMs) are smaller and less expensive instruments that operate at lower energies and can image the surface of a material in its original form. SEMs can map the elemental composition of rocks right out of the ground, identify single nanoscale defects in hundreds of thousands of computer chips, and even print 3D microscale prototypes. In addition to their day jobs as imaging tools, TEMs have recently taken up a side hustle as a workbench for quantum-mechanics experiments. Now, researchers from the University of Erlangen-Nuremberg in Germany have built an SEM with quantum credentials [1*].

    One avenue for quantum experiments in an electron microscope involves simultaneously shooting electrons and a laser beam at a material so that electrons inelastically scatter with the laser photons[2]. Electrons cannot absorb or emit a photon in free space as doing so would violate conservation of energy and momentum. However, a material offers just the kick needed to conserve both energy and momentum so an electron can exchange photons with the laser field [3]. An electron energy spectrum recorded after many electrons have participated in this inelastic electron-light interaction shows a range of evenly spaced peaks separated by the photon energy of the laser (Fig. 1). Because the laser field essentially behaves in a classical way, electrons emerge from the interaction in a controllable, nearly pure quantum state—in other words, the laser can be used to shape the electron state. And the electron state is special: a train of attosecond electron pulses forms with a period equal to the optical cycle of the laser [4]. These pulses could probe the fastest dynamics in materials [4]. A second interaction can then reverse the first one—and restore the original electron state—through destructive interference [5]. Inelastic electron-light scattering (IELS) can prepare electrons into an engineered quantum state for the purposes of imaging or studying quantum interactions.

    Between the potential to directly image the fastest material dynamics at atomic scales and the ability to engineer electron states using a laser, excitement has grown recently about IELS. For example, on the basic quantum side, researchers have used IELS to swirl electrons into a vortex state [6]. On the applied side, imaging with IELS is called photon-induced near-field electron microscopy (PINEM). PINEM has imaged the optical properties of systems such as surface plasmons and nanoparticles [2], proteins and cells [7], and even chiral nanostructures [8]. The SEM built by the University of Erlangen-Nuremberg team is capable of both performing quantum-mechanics experiments with electrons and imaging challenging specimens with PINEM.

    PINEM was first developed in a TEM, an area where electron spectrometers are commercially available. Measuring the quantized change in electron energy that occurs when electrons interact with the laser field is relatively easy. The tricky part is achieving a high laser field: femtosecond or picosecond electron and laser pulses are typically used for the combination of high peak fields and low average power [3]. For multiple IELS interactions, which are necessary for more elaborate engineering of the electron state, the millimeter-scale gap where specimens sit in a TEM limits the tool’s versatility, whereas SEMs have a large specimen chamber that the operator can reach into with both hands, making experiments with multiple IELS interactions easier. The lower available electron energies of an SEM may also prove useful for a range of specimens; there may be resonances or other maxima in the electron-light scattering depending on geometry [7, 8], or the PINEM signal may be too weak at TEM energies to effectively image the specimen but sufficiently strong at lower energies [3, 8]. Additionally, the lower cost of SEMs makes them more accessible to new groups wanting to do IELS or PINEM experiments.

    The instrument that the team developed makes PINEM possible in an SEM. They modified an electron source to produce picosecond electron pulses when struck by a laser pulse, added a path for a femtosecond pulsed laser to excite the specimen, and built an electron spectrometer for their SEM. Each of these steps is a significant project, but the group really triumphed by tying all the elements together: they characterized the instrument and probed a tungsten needle with PINEM. The measured electron spectra matched their simulations remarkably well, which suggests that they have an excellent understanding of the instrument they designed.

    It will be exciting to see what experiments follow with this instrument. The ample space in an SEM chamber allowed this group to place a lens with a short focal length very close to the specimen. Doing so may allow them to produce a high laser field on the specimen. The tightly focused laser spot leads to a higher PINEM signal without increasing the average temperature of the specimen, making specimens with a weaker optical response more practical to image. PINEM in an SEM could also shed new light on larger specimens, such as a 3D metamaterial device, that do not fit into a TEM. This new microscope may help motivate the increasing availability of commercial SEM electron spectrometers, which would make building future PINEM-SEMs far easier. The wide-open specimen chamber and the uniquely low energy range give this instrument the ability to push the limits of PINEM imaging and of quantum experiments with electrons.

    *References

    R. Shiloh et al., “Quantum-coherent light-electron interaction in a scanning electron microscope,” Phys. Rev. Lett. 128, 235301 (2022).
    B. Barwick et al., “Photon-induced near-field electron microscopy,” Nature 462, 902 (2009).
    S. T. Park et al., “Photon-induced near-field electron microscopy (PINEM): theoretical and experimental,” New J. Phys. 12, 123028 (2010).
    K. E. Priebe et al., “Attosecond electron pulse trains and quantum state reconstruction in ultrafast transmission electron microscopy,” Nat. Photon. 11, 793 (2017).
    K. E. Echternkamp et al., “Ramsey-type phase control of free-electron beams,” Nat. Phys. 12, 1000 (2016).
    G. M. Vanacore et al., “Ultrafast generation and control of an electron vortex beam via chiral plasmonic near fields,” Nat. Mater. 18, 573 (2019).
    T. R. Harvey et al., “Probing chirality with inelastic electron-light scattering,” Nano Lett. 20, 4377 (2020).
    N. Talebi, “Strong interaction of slow electrons with near-field light visited from first principles,” Phys. Rev. Lett. 125, 080401 (2020).

    See the full article here .


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    Please help promote STEM in your local schools.

    http://www.stemedcoalition.org/”>Stem Education Coalition

    physicsworld is a publication of the Institute of Physics. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

    We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.

     
  • richardmitnick 1:32 pm on June 3, 2022 Permalink | Reply
    Tags: , "Using mirrors lasers and lenses to bend light into a vortex ring", , Laser Technology, , University of Shanghai for Science and Technology [上海理工大学](CN)   

    From “phys.org” and University of Shanghai for Science and Technology [上海理工大学](CN): “Using mirrors lasers and lenses to bend light into a vortex ring” 

    From “phys.org”

    June 3, 2022
    Bob Yirka

    1
    Schematic of the experimental apparatus. A chirped pulse from the laser source splits into a signal pulse and a reference pulse. The signal pulse transforms to a spatiotemporal vortex (STOV) pulse after a 2D pulse shaper. The spatiotemporal vortex is stretched along the vortex line and is then converted into a toroidal vortex through an afocal conformal mapping system. The toroidal vortex is characterized by interference with the dechirped reference pulse. Credit: Nature Photonics (2022).

    A team of researchers from the University of Shanghai for Science and Technology and the University of Dayton has developed a way to bend light into a vortex ring using mirrors, lasers and lenses. In their study, published in the journal Nature Photonics, the group built on work done by other teams in which vortex rings were observed incidentally, and then mathematically designed a system that could generate them on demand.

    In 2016, another team of researchers discovered that under the right circumstances, strong pulses of light swirling around a central pipe-shaped pulse, could sometimes form into a donut-shaped vortex. Intrigued by the finding, the researchers with this new effort began to wonder if it might be possible to create such vortex rings on demand.

    They started by studying the properties and conditions that had led to the formations observed by the team in 2016 and applied mathematics to the problem. They found solutions that appeared to show how such rings could be made—solutions to Maxwell’s equations, in particular, they found, could be used to generate the kind of conformal mapping required.

    The researchers put together a combination of materials that would lead to a real-world implementation of their math solutions. They started by modifying a standard laser to generate a specific type of pulse. They added mirrors, lenses, gratings and special types of liquid crystal screens for the pulses to pass through. Each of the parts impacted the light in a specific way.

    The researchers note that the system first changed the pulses of light into a long, narrow shape, which gave other parts of the light something to swirl around. After the other light traveled through the system, the swirling light joined, like winds in a tornado, forming a ring.

    The researchers plan to continue their work, hoping to learn whether other vortex shapes can be made. They note that their work could provide blueprints for others looking to better understand the formation of toroidal vortices that form naturally.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    About Science X in 100 words
    Science X is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004 (Physorg.com), Science X’s readership has grown steadily to include 5 million scientists, researchers, and engineers every month. Science X publishes approximately 200 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Science X community members enjoy access to many personalized features such as social networking, a personal home page set-up, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

    Mission: 12 reasons for reading daily news on Science X Organization Key editors and writers include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
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