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  • richardmitnick 8:25 pm on September 16, 2019 Permalink | Reply
    Tags: , , , , , UCSB   

    From UC Santa Barbara: “A Quantum Leap” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    September 16, 2019
    James Badham

    $25M grant makes UC Santa Barbara home to the nation’s first NSF-funded Quantum Foundry, a center for development of materials and devices for quantum information-based technologies.

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    Professors Stephen Wilson and Ania Bleszynski Jayich will co-direct the campus’s new Quantum Foundry

    We hear a lot these days about the coming quantum revolution. Efforts to understand, develop, and characterize quantum materials — defined broadly as those displaying characteristics that can be explained only by quantum mechanics and not by classical physics — are intensifying.

    Researchers around the world are racing to understand these materials and harness their unique qualities to develop revolutionary quantum technologies for quantum computing, communications, sensing, simulation and other quantum technologies not yet imaginable.

    This week, UC Santa Barbara stepped to the front of that worldwide research race by being named the site of the nation’s first Quantum Foundry.

    Funded by an initial six-year, $25-million grant from the National Science Foundation (NSF), the project, known officially as the UC Santa Barbara NSF Quantum Foundry, will involve 20 faculty members from the campus’s materials, physics, chemistry, mechanical engineering and computer science departments, plus myriad collaborating partners. The new center will be anchored within the California Nanosystems Institute (CNSI) in Elings Hall.

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    California Nanosystems Institute

    The grant provides substantial funding to build equipment and develop tools necessary to the effort. It also supports a multi-front research mission comprising collaborative interdisciplinary projects within a network of university, industry, and national-laboratory partners to create, process, and characterize materials for quantum information science. The Foundry will also develop outreach and educational programs aimed at familiarizing students at all levels with quantum science, creating a new paradigm for training students in the rapidly evolving field of quantum information science and engaging with industrial partners to accelerate development of the coming quantum workforce.

    “We are extremely proud that the National Science Foundation has chosen UC Santa Barbara as home to the nation’s first NSF-funded Quantum Foundry,” said Chancellor Henry T. Yang. “The award is a testament to the strength of our University’s interdisciplinary science, particularly in materials, physics and chemistry, which lie at the core of quantum endeavors. It also recognizes our proven track record of working closely with industry to bring technologies to practical application, our state-of-the-art facilities and our educational and outreach programs that are mutually complementary with our research.

    “Under the direction of physics professor Ania Bleszynski Jayich and materials professor Stephen Wilson the foundry will provide a collaborative environment for researchers to continue exploring quantum phenomena, designing quantum materials and building instruments and computers based on the basic principles of quantum mechanics,” Yang added.

    Said Joseph Incandela, the campus’s vice chancellor for research, “UC Santa Barbara is a natural choice for the NSF quantum materials Foundry. We have outstanding faculty, researchers, and facilities, and a great tradition of multidisciplinary collaboration. Together with our excellent students and close industry partnerships, they have created a dynamic environment where research gets translated into important technologies.”

    “Being selected to build and host the nation’s first Quantum Foundry is tremendously exciting and extremely important,” said Rod Alferness, dean of the College of Engineering. “It recognizes the vision and the decades of work that have made UC Santa Barbara a truly world-leading institution worthy of assuming a leadership role in a mission as important as advancing quantum science and the transformative technologies it promises to enable.”

    “Advances in quantum science require a highly integrated interdisciplinary approach, because there are many hard challenges that need to be solved on many fronts,” said Bleszynski Jayich. “One of the big ideas behind the Foundry is to take these early theoretical ideas that are just beginning to be experimentally viable and use quantum mechanics to produce technologies that can outperform classical technologies.”

    Doing so, however, will require new materials.

    “Quantum technologies are fundamentally materials-limited, and there needs to be some sort of leap or evolution of the types of materials we can harness,” noted Wilson. “The Foundry is where we will try to identify and create those materials.”

    Research Areas and Infrastructure

    Quantum Foundry research will be pursued in three main areas, or “thrusts”:

    • Natively Entangled Materials, which relates to identifying and characterizing materials that intrinsically host anyon excitations and long-range entangled states with topological, or structural, protection against decoherence. These include new intrinsic topological superconductors and quantum spin liquids, as well as materials that enable topological quantum computing.

    • Interfaced Topological States, in which researchers will seek to create and control protected quantum states in hybrid materials.

    • Coherent Quantum Interfaces, where the focus will be on engineering materials having localized quantum states that can be interfaced with various other quantum degrees of freedom (e.g. photons or phonons) for distributing quantum information while retaining robust coherence.

    Developing these new materials and assessing their potential for hosting the needed coherent quantum state requires specialized equipment, much of which does not exist yet. A significant portion of the NSF grant is designated to develop such infrastructure, both to purchase required tools and equipment and to fabricate new tools necessary both to grow and characterize the quantum states in the new materials, Wilson said.

    UC Santa Barbara’s deep well of shared materials growth and characterization infrastructure was also a factor in securing the grant. The Foundry will leverage existing facilities, such as the large suite of instrumentation shared via the Materials Research Lab and the California Nanosystems Institute, multiple molecular beam epitaxy (MBE) growth chambers (the university has the largest number of MBE apparatuses in academia), unique optical facilities such as the Terahertz Facility, state-of-the-art clean rooms, and others among the more than 300 shared instruments on campus.

    Data Science

    NSF is keenly interested in both generating and sharing data from materials experiments. “We are going to capture Foundry data and harness it to facilitate discovery,” said Wilson. “The idea is to curate and share data to accelerate discovery at this new frontier of quantum information science.”

    Industrial Partners

    Industry collaborations are an important part of the Foundry project. UC Santa Barbara’s well-established history of industrial collaboration — it leads all universities in the U.S. in terms of industrial research dollars per capita — and the application focus that allows it to to transition ideas into materials and materials into technologies, was important in receiving the Foundry grant.

    Another value of industrial collaboration, Wilson explained, is that often, faculty might be looking at something interesting without being able to visualize how it might be useful in a scaled-up commercial application. “If you have an array of directions you could go, it is essential to have partners to help you visualize those having near-term potential,” he said.

    “This is a unique case where industry is highly interested while we are still at the basic-science level,” said Bleszynski Jayich. “There’s a huge industry partnership component to this.”

    Among the 10 inaugural industrial partners are Microsoft, Google, IBM, Hewlett Packard Enterprises, HRL, Northrop Grumman, Bruker, SomaLogic, NVision, and Anstrom Science. Microsoft and Google have substantial campus presences already; Microsoft’s Quantum Station Q lab is here, and UC Santa Barbara professor and Google chief scientist John Martinis and a team of his Ph.D. student researchers are working with Google at its Santa Barbara office, adjacent to campus, to develop Google’s quantum computer.

    Undergraduate Education

    In addition, with approximately 700 students, UC Santa Barbara’s undergraduate physics program is the largest in the U.S. “Many of these students, as well as many undergraduate engineering and chemistry students, are hungry for an education in quantum science, because it’s a fascinating subject that defies our classical intuition, and on top of that, it offers career opportunities. It can’t get much better than that,” Bleszynski Jayich said.

    Graduate Education Program

    Another major goal of the Foundry project is to integrate quantum science into education and to develop the quantum workforce. The traditional approach to quantum education at the university level has been for students to take physics classes, which are focused on the foundational theory of quantum mechanics.

    “But there is an emerging interdisciplinary component of quantum information that people are not being exposed to in that approach,” Wilson explained. “Having input from many overlapping disciplines in both hard science and engineering is required, as are experimental touchstones for trying to understand these phenomena. Student involvement in industry internships and collaborative research with partner companies is important in addressing that.”

    “We want to introduce a more practical quantum education,” Bleszynski Jayich added. “Normally you learn quantum mechanics by learning about hydrogen atoms and harmonic oscillators, and it’s all theoretical. That training is still absolutely critical, but now we want to supplement it, leveraging our abilities gained in the past 20 to 30 years to control a quantum system on the single-atom, single-quantum-system level. Students will take lab classes where they can manipulate quantum systems and observe the highly counterintuitive phenomena that don’t make sense in our classical world. And, importantly, they will learn various cutting-edge techniques for maintaining quantum coherence.

    “That’s particularly important,” she continued, “because quantum technologies rely on the success of the beautiful, elegant theory of quantum mechanics, but in practice we need unprecedented control over our experimental systems in order to observe and utilize their delicate quantum behavior.”

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition


    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 5:25 pm on March 13, 2019 Permalink | Reply
    Tags: , , , Comet, Controversial from the time it was proposed the hypothesis even now continues to be contested by those who prefer to attribute the end-Pleistocene reversal in warming entirely to terrestrial causes., , , Kennett and fellow stalwarts of the Younger Dryas Boundary (YDB) Impact Hypothesis have recently received a major boost:, , The discovery of a very young 31-kilometer-wide impact crater beneath the Greenland ice sheet which they believe may have been one of the many comet fragments that impacted Earth at the onset of the Y, The layer containing these spherules also show peak concentrations of platinum and gold and native iron particles rarely found in nature, The Pilauco dig site in a suburb of the Osorno province in Chile, The presence of microscopic spherules interpreted to have been formed by melting due to the extremely high temperatures associated with impact, They believe this may have been one of the many comet fragments that impacted Earth at the onset of the Younger Dryas., UC Santa Barbara geology professor emeritus James Kennett, UCSB, Younger Dryas Impact Hypothesis   

    From UC Santa Barbara: “The Day the World Burned” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    March 8, 2019
    Sonia Fernandez

    1
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    The researchers found evidence of cosmic impact at the Pilauco dig site in a suburb of the Osorno province in Chile. Photo Credit: Courtesy Image

    When UC Santa Barbara geology professor emeritus James Kennett and colleagues set out years ago to examine signs of a major cosmic impact that occurred toward the end of the Pleistocene epoch, little did they know just how far-reaching the projected climatic effect would be.

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    James Kennett. Photo Credit: Sonia Fernandez

    “It’s much more extreme than I ever thought when I started this work,” Kennett noted. “The more work that has been done, the more extreme it seems.”

    He’s talking about the Younger Dryas Impact Hypothesis, which postulates that a fragmented comet slammed into the Earth close to 12,800 years ago, causing rapid climatic changes, megafaunal extinctions, sudden human population decrease and cultural shifts and widespread wildfires (biomass burning). The hypothesis suggests a possible triggering mechanism for the abrupt changes in climate at that time, in particular a rapid cooling in the Northern Hemisphere, called the Younger Dryas, amid a general global trend of natural warming and ice sheet melting evidenced by changes in the fossil and sediment record.

    Controversial from the time it was proposed, the hypothesis even now continues to be contested by those who prefer to attribute the end-Pleistocene reversal in warming entirely to terrestrial causes. But Kennett and fellow stalwarts of the Younger Dryas Boundary (YDB) Impact Hypothesis, as it is also known, have recently received a major boost: the discovery of a very young, 31-kilometer-wide impact crater beneath the Greenland ice sheet, which they believe may have been one of the many comet fragments that impacted Earth at the onset of the Younger Dryas.

    Now, in a paper published in the journal Nature Scientific Reports, Kennett and colleagues, led by Chilean paleontologist Mario Pino, present further evidence of a cosmic impact, this time far south of the equator, that likely lead to biomass burning, climate change and megafaunal extinctions nearly 13,000 years ago.

    “We have identified the YDB layer at high latitudes in the Southern Hemisphere at near 41 degrees south, close to the tip of South America,” Kennett said. This is a major expansion of the extent of the YDB event.” The vast majority of evidence to date, he added, has been found in the Northern Hemisphere.

    This discovery began several years ago, according to Kennett, when a group of Chilean scientists studying sediment layers at a well-known Quaternary paleontological and archaeological site, Pilauco Bajo, recognized changes known to be associated with YDB impact event. They included a “black mat” layer, 12,800 years in age, that coincided with the disappearance of South American Pleistocene megafauna fossils, an abrupt shift in regional vegetation and a disappearance of human artifacts.

    “Because the sequencing of these events looked like what had already been described in the YDB papers for North America and Western Europe, the group decided to run analyses of impact-related proxies in search of the YDB layer,” Kennett said. This yielded the presence of microscopic spherules interpreted to have been formed by melting due to the extremely high temperatures associated with impact. The layer containing these spherules also show peak concentrations of platinum and gold, and native iron particles rarely found in nature.

    “Among the most important spherules are those that are chromium-rich,” Kennett explained. The Pilauco site spherules contain an unusual level of chromium, an element not found in Northern Hemisphere YDB impact spherules, but in South America. “It turns out that volcanic rocks in the southern Andes can be rich in chromium, and these rocks provided a local source for this chromium,” he added. “Thus, the cometary objects must have hit South America as well.”

    Other evidence, which, Kennett noted, is consistent with previous and ongoing documentation of the region by Chilean scientists, pointed to a “very large environmental disruption at about 40 degrees south.” These included a large biomass burning event evidenced by, among other things, micro-charcoal and signs of burning in pollen samples collected at the impact layer. “It’s by far the biggest burn event in this region we see in the record that spans thousands of years,” Kennett said. Furthermore, he went on, the burning coincides with the timing of major YDB-related burning events in North America and western Europe.

    The sedimentary layers at Pilauco contain a valuable record of pollen and seeds that show change in character of regional vegetation — evidence of a shifting climate. However, in contrast to the Northern Hemisphere, where conditions became colder and wetter at the onset of the Younger Dryas, the opposite occurred in the Southern Hemisphere.

    “The plant assemblages indicate that there was an abrupt and major shift in the vegetation from wet, cold conditions at Pilauco to warm, dry conditions,” Kennett said. According to him, the atmospheric zonal climatic belts shifted “like a seesaw,” with a synergistic mechanism, bringing warming to the Southern Hemisphere even as the Northern Hemisphere experienced cooling and expanding sea ice. The rapidity — within a few years — with which the climate shifted is best attributed to impact-related shifts in atmospheric systems, rather than to the slower oceanic processes, Kennett said.

    Meanwhile, the impact with its associated major environmental effects, including burning, is thought to have contributed to the extinction of local South American Pleistocene megafauna — including giant ground sloths, sabretooth cats, mammoths and elephant-like gomphotheres — as well as the termination of the culture similar to the Clovis culture in the north, he added. The amount of bones, artifacts and megafauna-associated fungi that were relatively abundant in the soil at the Pilauco site declined precipitously at the impact layer, indicating a major local disruption.

    The distance of this recently identified YDB site — about 6,000 kilometers from the closest well-studied site in South America — and its correlation with the many Northern Hemispheric sites “greatly expands the extent of the YDB impact event,” Kennett said. The sedimentary and paleo-vegetative evidence gathered at the Pilauco site is in line with previous, separate studies conducted by Chilean scientists that indicate a widespread burn and sudden major climate shifts in the region at about YDB onset. This new study further bolsters the hypothesis that a cosmic impact triggered the atmospheric and oceanic conditions of the Younger Dryas, he said.

    “This is further evidence that the Younger Dryas climatic onset is an extreme global event, with major consequences on the animal life and the human life at the time,” Kennett said. “And this Pilauco section is consistent with that.”

    Research on this study was also conducted by Ana Abarzúa, Giselle Astorga, Alejandra Martel-Cea, Nathalie Cossio, Maria Paz Lira and Rafael Labarca of Universidad Austral de Chile; R. Ximena Navarro of Universidad Católica de Temuco; and Malcolm A. LeCompte and Victor Adedeji of Elizabeth City State University. Christopher Moore of University of South Carolina; Ted E. Bunch and Charles Mooney of Northern Arizona University; and Wendy S. Wolbach of DePaul University contributed research, as did Allen West of Comet Research Group.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 11:12 am on January 29, 2019 Permalink | Reply
    Tags: A new kind of behavior associated with supermassive black holes, A new third kind of flare-one longer lived than a star being ripped apart and not as constant as a quasar, , , , Black hole studies, , UCSB   

    From UC Santa Barbara: “A New Kind of Black Hole Activity” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    January 23, 2019
    Harrison Tasoff

    Supermassive black hole depiction with accretion disk with jets streaming out in opposite directions- all encompassed by a dusty torus. Credit NASA-CXC-CfA-R .Kraft et al. and MPIFR-ESO-APEX

    NASA/Chandra X-ray Telescope

    ESO/MPIFR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft)

    Astrophysicist Andy Howell, an adjunct faculty member in the physics department at UC Santa Barbara and a staff scientist at Las Cumbres Observatory (LCO), and his colleagues have revealed a new kind of behavior associated with supermassive black holes. The Goleta-based observatory recently published the following announcement detailing the findings.

    Supermassive black holes, the type at the centers of galaxies that are millions or billions times the mass of the Sun, were thought to eat and grow in only two ways: either by ripping apart a star in a Tidal Disruption Event (TDE), or by nearly continuous accretion from a disk of material as is seen in a quasar or radio galaxy – this phenomenon is known as Active Galactic Nuclei (AGN). In new research published today in Nature Astronomy, astronomers have seen several examples of a new third kind of flare, one longer lived than a star being ripped apart and not as constant as a quasar.

    The new phenomenon was revealed by an international team of astronomers led by Benny Trakhtenbrot of Tel Aviv University in a tour de force of observations spanning observatories around the world and in space, including data from NASA’s Swift and NuSTAR satellites, the NICER (Neutron star Interior Composition Explorer) instrument on the International Space Station, and Las Cumbres Observatory, a globe-spanning network of robotic telescopes.

    NASA Neil Gehrels Swift Observatory

    NASA NuSTAR X-ray telescope

    NASA NICER on the ISS


    NASA/NICER on the ISS

    LCO_map_2017. Map of the Las Cumbres Observatory global network of robotic telescopes

    In a normal AGN or quasar, the brightness of the center part of the galaxy fluctuates over many years as the black hole devours material from an accretion disk, similar to water flowing down a bathtub drain. Material spins ever-more quickly as it approaches the black hole, causing it to glow in optical, ultraviolet light and x-rays. In a Tidal Disruption Event, a star is ripped apart by the black hole, causing a large single spike in brightess that only lasts for a few months. In the new class of flares, the area around the black hole increases in optical and ultraviolet emission by about 50%, and in x-rays by factors of several, for more than a year before fading.

    The new finding began with the discovery of Astronomical Transient AT 2017bgt by the ASAS-SN network of telescopes.

    Soon after, astronomers at Las Cumbres Observatory started monitoring the transient with their network of ground-based telescopes and noticed behavior never before seen. The team also triggered space-based observations to observe the ultraviolet and x-ray properties, as photons at those high energies are blocked by the Earth’s atmosphere. Later, they found another two other examples of similar phenomena around other supermassive black holes in other galaxies, establishing it as a new class of black hole feeding.

    ASAS-SN’s hardware. Off the shelf Mark Elphick-Los Cumbres Observatory

    Andy Howell, staff scientist at LCO and a coauthor on the study said, “It is remarkable to have three different x-ray facilities in orbit, Swift, NICER, and NuSTAR, working together to help us see the extraordinarily high energies radiated near this black hole. But they only tell part of the story. Long-term ground-based monitoring was also necessary to have observations that stretch over more than a year, and that’s exactly what LCO was built for.”

    Howell draws an analogy with water: “An AGN is like getting rained on — a constant trickle that might vary a bit in intensity, but lasts for a while. A tidal disruption event is like getting hit by a sprinkler — there’s just one stream of water, and it might be more intense than rain. But this new kind of flare is like getting hit by a firehose in the face. Now we have to figure out, ‘How the hell did nature produce that that?’ Black holes are even weirder than we thought.”

    Astronomers are confounded as to how a stream of material apparently bigger than a star flows around the black hole to produce such emission. As it is the first time such a phenomenon has been seen, it has not yet been simulated.

    Since it remains unknown how black holes grow in size from something only a few times the mass of the sun up to, in the case of AT 2017bgt, 14-million times the mass of the Sun, astronomers are excited to get any new insight into the process of how black holes eat and grow. “We are trying to find all the different ways black holes gain mass with LCO at the center of this effort,” says Iair Arcavi, formerly a postdoc at LCO and now a faculty member at Tel Aviv University and a co-author on the study, “maybe now we’ll finally solve the riddle of how nature makes these monsters that lie at the center of every galaxy.”

    See the full article here .


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

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 11:26 am on November 15, 2018 Permalink | Reply
    Tags: , As an indicator of the impacts of climate change Arctic sea ice is hard to beat, “Right now the prediction is that in about 20 years we will see an [Arctic] ice-free summer, , Reports on the ground indicate the ice is melting at a much faster rate than predicted by global climate models, Simulation Versus Observation, The effects of changes in the Arctic are no longer confined to the region and in fact spread to the mid-latitudes — often in the form of cold weather outbreaks, The importance of anthropogenic forcing, UCSB   

    From UC Santa Barbara: “Simulation Versus Observation” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    November 13, 2018
    Sonia Fernandez
    (805) 893-4765
    sonia.fernandez@ucsb.edu

    The gap between simulated prediction and real-life observation in Arctic sea ice melt can be attributed to complicated internal drivers.

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    Arctic sea ice

    As an indicator of the impacts of climate change, Arctic sea ice is hard to beat. Scientists have observed the frozen polar ocean advance and retreat at this most sensitive region of the Earth over decades for insight on the potential ripple effects on assorted natural systems: global ocean circulation, surrounding habitats and ecosystems, food sources, sea levels and more.

    Despite efforts to make model simulations more closely mirror actual observations of Arctic sea ice melt, however, a gap has opened: Reports on the ground indicate the ice is melting at a much faster rate than predicted by global climate models.

    “Based on this phenomenon, people have different opinions,” said UC Santa Barbara climate scientist Qinghua Ding, an assistant professor in the campus’s Earth Research Institute. The consensus of the climate science community, he said, is leaning toward the idea that the discrepancy is due to flawed modeling. “It’s something like the model has some bias; it has some low sensitivity to anthropogenic forcing,” he explained.

    Ding and his group disagree. In a study titled Fingerprints of internal drivers of Arctic sea ice loss in observations and model simulations, published in the journal Nature Geoscience, the group says the models are just fine. About 40 to 50 percent of sea ice loss over the last three decades, they argue, is attributable to significant but as yet little-understood internal drivers — among them effects that originate partially as far away as the tropics.

    “Actually, we’re comparing apples to oranges,” Ding said of the discrepancy between real-time observation and simulated Arctic ice melt driven by anthropogenic forcing. The average of models, he explained, accounts only for what effects are a result of historical radiative forcing — calculations based mostly on levels of greenhouse gases — but don’t rely on, for instance, the short-term variations in sea surface temperatures, humidity, atmospheric pressure and other factors both local and connected to other phenomena elsewhere on Earth. Such higher-frequency events often show up as noise in the repeated, individual runs of the simulations as scientists look for general long-term trends.

    “Any one run of a model will have random noise,” said Bradley Markle, a postdoctoral scholar in Ding’s research group. “If you take 20 or 30 runs of a model, they will each have their own random noise, but they will cancel each other out.” The resulting value is the average of all the simulation runs without the random variability. But that random variability may also be impacting what is being observed out on the ice, in addition to the forced signal.

    Due to their nature, internal variabilities are also likely to result in periods in which Arctic ice melt will appear to slow or even reverse, but in the bigger picture, climate scientists still see the eventual complete melting of Arctic sea ice for part of the year.

    “There are so many reasons we focus on Arctic sea ice, but one of the main things people really care about is the timing of the ice-free summer,” said Ding, referring to a time when the northern pole will no longer be the frozen frontier it has been even in the summer.

    “Right now, the prediction is that in about 20 years, we will see an ice-free summer,” Ding said. More than just a climate issue, he continued, the ice-free summer is also a societal issue, given the effects on fisheries and other food sources as well as natural resources and habitats that benefit from a frozen polar ocean. One of the things this discrepancy between simulation and observation indicates, he said, is that predictions about when this ice-free summer occurs will have to be tempered with some acknowledgement of the effects of internal variabilities.

    “There’s a large uncertainty associated with this time window,” Ding said. “As we consider internal variabilities, plus CO2 forcing, we should be more cautious about the timing of the ice-free summer.”

    For Markle, this situation highlights the disconnect that often occurs when talking about long-term climate trends versus short-term observations. Over the course of our human timescales of hours to days, we experience atmospheric temperature changes over several degrees, so a mean global temperature rise of one or two degrees doesn’t seem all that significant.

    “Likewise, year-to-year temperature variability, such as that associated with these tropical internal variations, can be several degrees in annual average temperature in a specific area, so near the same magnitude as the centuries-long global warming signal,” he said.

    An example of this relatively short-term climate variability is the well-known El Niño Southern Oscillation (ENSO), the constant tipping between the El Niño and counterpart La Niña weather systems that brings both drought and rain, scarcity and abundance to different parts of the world. More extreme ENSO-driven weather behavior is expected as the Earth’s climate seeks equilibrium in the face of an average global temperature increase of even a couple degrees.

    “Just for reference, 20,000 years ago there was an ice sheet covering most of Canada during the height of the last ice age — that was a four- or five-degree annual average temperature change,” Markle said, “but it’s a huge difference.”

    Ding’s research group continues to investigate the mysterious and complex internal drivers that affect Arctic sea ice, particularly those that originate in the warm, wet tropics.

    “We’re mostly interested in the period from the early 2000s to the present day, where we see such strong melting,” said graduate student Ian Baxter, who also works with Ding. It’s known, he added, that the effects of changes in the Arctic are no longer confined to the region and in fact spread to the mid-latitudes — often in the form of cold weather outbreaks. The group is interested in how effects in the tropics could spread beyond that region and affect the Arctic.

    “We’re trying to lay out a mechanism through which that happens,” Baxter said.

    See the full article here .


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

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 10:54 am on October 4, 2018 Permalink | Reply
    Tags: , Bentson Foundation, , UCSB   

    From UC Santa Barbara: “Scholars on Board” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    October 2, 2018
    Shelly Leachman

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    UC Santa Barbara Bentson Scholar Ally Aplin. Photo Credit: Courtesy image

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    UC Santa Barbara Bentson Scholar Daniel Baldwin. Photo Credit: Courtesy image

    With new support for its Bentson Scholars Program, the Bentson Foundation secures future opportunities for outstanding students in marine science.

    It was a partnership that made perfect sense.

    Alumni Laurie Bentson Kauth and William Kauth both graduated from UC Santa Barbara and have stayed local ever since. When William shifted career gears from fisherman to marine biology teacher at Santa Barbara High School, he frequently visited the campus with his students. The couple raised a daughter so passionate about the ocean she became a maritime lawyer.

    Their Bentson Foundation has long held a focus on public education and student support. So it came to be that in 2014 they launched the Bentson Scholars Programat UC Santa Barbara , a merit-based initiative for undergraduates with an interest in aquatic biology. They have now cemented the program for generations, with a new gift of $1 million to endow the fund based in the Department of Ecology, Evolution and Marine Biology (EEMB).

    “We had always been back and forth with UCSB about this idea, so it was a natural thing to do, and it’s been more successful than we ever imagined,” said Bentson Kauth, whose parents, Larry and Nancy Bentson, started the Bentson Foundation in 1956. “UCSB and the team there have taken this program under their wing and made it even better than we ever dreamed it could be. The students are phenomenal. Every single one is beyond belief and each in a different way, but all related to marine science.

    “That’s the whole idea — to get the brightest and the best and get them working on this topic,” she added. “The oceans and marine science are more important now than ever.”

    The substantial Bentson Scholarship covers part of tuition and reduces the need to work, while also providing hands-on enrichment and research opportunities that enable scholars to immediately apply lessons from the classroom in the field.

    It’s a win-win for the students and faculty alike, according to Craig Carlson, a professor and vice chair in EEMB, who oversees the program.

    “The generous fellowships provided by the Bentson Foundation afford unique opportunities and experiences that take these outstanding students to the next level,” Carlson said. “These fellowships are often real difference-makers that allow these students to reach their academic and research goals.”

    Those sentiments are echoed resoundingly by the students themselves, who attest to the scholarship’s impact on their academic pursuits and future aspirations.

    “Without the Bentson Scholarship, I wouldn’t have as many of the opportunities that I now have in front of me,” said Ally Aplin, a pre-biology major in the class of 2021. “This scholarship allows me to be involved in incredible research opportunities to further my field of knowledge in a way that I never could in a classroom, and to help me to achieve my goal of being a part of the fight to save coral reefs.”

    That’s exactly what the Bentson Foundation wants to hear from its scholars, according to Judi Dutcher, executive director.

    “Looking toward the horizon, these scholars are going to have an impact in the field,” Dutcher said. “The decision to amplify our support with this new gift really is an outgrowth of the fact that we’ve been really pleased with the caliber of the students and the difference we’ve seen that they have made.

    “Our support has been paid back ten-fold in terms of the leaders that they become and the testimonials they give in regards to what impact the scholarship has had,” Dutcher continued. “I would encourage any other donor or foundation, if you are considering something similar — whatever their field of interest — do it, because you will immediately see the impact of your gift. And that’s so important. Start modestly and you’ll see.”

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 12:19 pm on July 11, 2018 Permalink | Reply
    Tags: , , , UCSB, UCSB BIFROST-The Broadly-tunable Illumination Facility for Research Outreach Scholarship and Training   

    From UC Santa Barbara: “Enter BIFROST” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    July 2, 2018
    Sonia Fernandez
    (805) 893-4765
    sonia.fernandez@ucsb.edu

    UCSB The Broadly-tunable Illumination Facility for Research, Outreach, Scholarship, and Training (BIFROST)Photo Credit:
    David Weld/UCSB

    In Norse mythology, the Bifrost was the rainbow bridge linking the realm of the gods to Earth. At UC Santa Barbara, it is also the name of the Broadly-tunable Illumination Facility for Research, Outreach, Scholarship, and Training (BIFROST), a laser facility that will provide coherent light throughout the visible and infrared spectrum to 10 laboratories in the campus’s Broida Hall, which houses the Department of Physics.

    Like the mythical bridge, BIFROST includes light at many different frequencies; unlike its more ephemeral namesake, it offers high-quality, tunable light, and is easily accessible to mortals.

    “This is something that we felt could really turbocharge a lot of different areas of research,” said David Weld, a professor of physics, who led the effort to bring the unique apparatus to the campus. Consisting of a titanium:sapphire laser with harmonic and sum frequency modules, and housed in its own central room in the building, BIFROST delivers laser light to several labs via a network of dedicated optical fibers.

    When the project is complete, individual research groups working with one or multiple specific frequencies of light will be able to conduct their studies efficiently, using a remote web-based interface to tune the laser, according to Weld. Condensed matter physicists can use the laser to explore the quantum mechanical properties of solids. Biophysicists can observe processes in individual molecules. And with the fine control provided by BIFROST, atomic physicists like Weld can precisely probe optical transitions.

    “If you want to drive particular transitions, then you need light of very specific colors,” Weld said. “And if you want to do it precisely, you need that light to be spectroscopy-grade.” Until BIFROST, expensive, individual devices that provided one color or another were necessary; with this “light-faucet,” not only will existing research be boosted, but new areas can be opened up.

    He added that the multi-user tunable spectroscopy-grade laser can also provide learning opportunities not always available to beginning physicists — namely, undergrads who can get an edge in their research and study with access to such an instrument.

    “The inability to get well characterized laser light of a particular frequency is very often the barrier that prevents an experiment from being feasible in the undergraduate labs,” he said.

    And it couldn’t come at a better time. UCSB has one of the fastest-growing populations of physics undergraduate students in the nation. Additionally, it is a minority-serving institution, a designation that enabled funding for BIFROST from the U.S. Department of Defense and the Army Research Office. The breadth of ongoing and future research the instrument can support and the opportunities it provides for education and STEM outreach, Weld noted, made the campus an ideal location for the half-million-dollar facility.

    See the full article here .


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

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 11:32 am on June 12, 2018 Permalink | Reply
    Tags: , , , , UCSB   

    From UC Santa Barbara: “Under the Sea” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    June 5, 2018
    Jeff Mitchell

    Earth scientist Zach Eilon plumbs the depths of the Pacific Ocean to learn more about plate tectonics.

    5
    The Pacific ORCA science party on board the research vessel Kilo Moana; UCSB’s Zach Eilon is seventh from left. Photo Credit: Courtesy Zach Eilon

    2
    Watchstanders processing data in the vessel’s computer lab spot an underwater volcano that has never before been imaged. Photo Credit: Courtesy Zach Eilon

    3
    Preparing to deploy an Ocean Bottom Seismometer (OBS) at sunset. Photo Credit: Courtesy Zach Eilon

    4
    Preparing to test all the OBS communication devices, temporarily housed in the “rosette”, sitting beneath the A-frame; the yellow packages on deck are the OBS instruments, awaiting deployment. Photo Credit: Courtesy Zach Eilon

    Voyaging across a vast swath of the Pacific Ocean to learn more about how the Earth’s tectonic plates work, scientist Zach​​ Eilon was assisted along the way by friendly deep-sea denizen SpongeBob SquarePants.

    No, the beloved animated character wasn’t really there, but SpongeBob was the nickname Eilon, a UC Santa Barbara assistant professor of earth sciences, gave the sophisticated instrument that played a key role in his research.

    Otherwise known as ocean bottom seismometers, or OBS’s, these instruments are sensitive enough to detect earthquakes on the other side of the world.

    While the seismometers themselves sit on the seafloor, they are attached to a bright yellow flotation package — hence, the SpongeBob comparison — and are about a meter in width. The packages are affixed to a plastic base containing complex electronics.

    Eilon and collaborators carefully placed 30 of them on the ocean floor about 2,000 miles southeast of Hawaii during their recent Pacific ORCA (Pacific OBS Research into Convecting Asthenosphere) expedition aboard the U.S. Navy research vessel Kilo Moana.

    2
    U.S. Navy research vessel Kilo Moana

    The trip and the experiment were part of an ongoing and high-profile international effort, on which UCSB is one of three lead institutions in the U.S., to seismically instrument the Pacific Ocean.

    Oceanic plates make up 70 percent of the Earth’s surface and offer important windows into the Earth’s mantle, Eilon said, yet they are largely unexplored due to the obvious challenge of putting sensitive electronics three miles beneath the sea surface. The earth science community has identified several unanswered questions regarding the thermal structure of oceanic plates, the significance of volcanism in the middle of oceanic plates and how the convecting mantle beneath the plates controls their movements.

    Undulations in the gravity field and unexplained shallowing of the ocean floors hint that small-scale convection may be occurring beneath the oceanic plates, but this remains unconfirmed, according to Eilon. The new experiment could help prove it.

    “Our little instruments will sit on the ocean floor for approximately 15 months, recording earthquakes around the world,” he said. “When we return to retrieve them next year they’ll hold seismic data in their memory banks that could change the way in which we understand the oceanic plates. That understanding is pretty significant, considering that these plates make up about 70 percent of our planet’s surface.”

    When they are recovered in July 2019, the OBS units are expected to provide data that allows Eilon and his collaborators to make 3-D images of the oceanic tectonic plates – a bit like taking a CAT-scan of the Earth. Of particular interest is the mysterious asthenosphere, the zone of Earth’s mantle lying beneath the lithosphere (the tectonic plate) and believed to be much hotter and more fluid than rocks closer to the surface. The asthenosphere extends from about 60 miles to about 250 miles below Earth’s surface.

    Once ready for deployment, the weighted instrument packages are designed to carefully sink upright to the seafloor. When the science party returns to the site, the ship will send an acoustic signal down to the individual science packages, commanding them to release the weight holding them down, allowing the buoyant yellow “SpongeBob” portion of the device to slowly float them to the surface, he explained.

    Once on the surface, the ship’s crew will home in on the package (which has a light, flag, and radio so the scientists can locate it) and lift it from the sea. From there the science team will commence the process of downloading the seismic data which are detailed records of the ocean floor vibrations. Turning these wiggles into 3D images is the result of highly complex computer processing and mathematics.

    Eilon said that in addition to giving researchers a better idea of how the Earth’s tectonic plates work, the data is expected to provide important information about geologic hazards.

    “By improving our understanding of interactions between plates, the data we collect should improve our ability to forecast earthquakes and volcanic eruptions,” he said, “which I hope will help authorities save lives when these events occur.”

    Eilon, along with co-principal investigator Jim Gaherty of Columbia University, led the expedition’s diverse 14-member science team (drawn from 11 institutions across three continents). The $4-million research project is supported by the National Science Foundation.

    See the full article here .


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

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 3:00 pm on April 17, 2018 Permalink | Reply
    Tags: Application, Complexity, Fidelity, Hello DARKNESS, , , The most advanced camera in the world, UCSB   

    From UCSB: Science + Technology 

    UC Santa Barbara Name bloc
    UC Santa Barbara

    Complexity, Fidelity, Application
    UCSB/Google researchers in quantum computing professor John Martinis’ group outline their plan for quantum supremacy

    By Sonia Fernandez
    (805) 893-4765
    sonia.fernandez@ucsb.edu
    Thursday, April 12, 2018

    1
    The dilution refrigerator, a cryogenic device where the quantum happens. Photo Credit: Eric Lucero/Google, Inc.

    2
    This superconducting chip, with a total area of one square centimeter, consists of nine qubits in a 1D array. Microwave pusles are applied to control their states and their interaction, and consequently control the dynamics of the system. Such Josephson-junction based superconducting systems are a leading physical implementations for quantum computation and simulation processing. Photo Credit: Eric Lucero/Google, Inc.

    Things are getting real for researchers in the UC Santa Barbara John Martinis/Google group. They are making good on their intentions to claim supremacy in a tight global race to build the first quantum machine to outperform the world’s best classical supercomputers.

    But what is quantum supremacy in a field where horizons are being widened on a regular basis, in which teams of the brightest quantum computing minds in the world routinely up the ante on the number and type of quantum bits (“qubits”) they can build, each with their own range of qualities?

    “Let’s define that, because it’s kind of vague,” said Google researcher Charles Neill. Simply put, he continued, “we would like to perform an algorithm or computation that couldn’t be done otherwise. That’s what we actually mean.”

    Neill is lead author of the group’s new paper, “A blueprint for demonstrating quantum supremacy with superconducting qubits,” now published in the journal Science.

    Fortunately, nature offers up many such complex situations, in which the variables are so numerous and interdependent that classical computers can’t hold all the values and perform the operations. Think chemical reactions, fluid interactions, even quantum phase changes in solids and a host of other problems that have daunted researchers in the past. Something on the order of at least 49 qubits — roughly equivalent to a petabyte (one million gigabytes) of classical random access memory — could put a quantum computer on equal footing with the world’s supercomputers. Just recently, Neill’s Google/Martinis colleagues announced an effort toward quantum supremacy with a 72-qubit chip possessing a “bristlecone” architecture that has yet to be put through its paces.

    But according to Neill, it’s more than the number of qubits on hand.

    “You have to generate some sort of evolution in the system which leads you to use every state that has a name associated with it,” he said. The power of quantum computing lies in, among other things, the superpositioning of states. In classical computers, each bit can exist in one of two states — zero or one, off or on, true or false — but qubits can exist in a third state that is a superposition of both zero and one, raising exponentially the number of possible states a quantum system can explore.

    Additionally, say the researchers, fidelity is important, because massive processing power is not worth much if it’s not accurate. Decoherence is a major challenge for anyone building a quantum computer — perturb the system, the information changes. Wait a few hundredths of a second too long, the information changes again.

    “People might build 50 qubit systems, but you have to ask how well it computed what you wanted it to compute,” Neill said. “That’s a critical question. It’s the hardest part of the field.” Experiments with their superconducting qubits have demonstrated an error rate of one percent per qubit with three- and nine-qubit systems, which, they say, can be reduced as they scale up, via improvements in hardware, calibration, materials, architecture and machine learning.

    Building a qubit system complete with error correction components — the researchers estimate a range of 100,000 to a million qubits — is doable and part of the plan. And still years away. But that doesn’t mean their system isn’t already capable of doing some heavy lifting. Just recently it was deployed, with spectroscopy, on the issue of many-body localization in a quantum phase change — a quantum computer solving a quantum statistical mechanics problem. In that experiment, the nine-qubit system became a quantum simulator, using photons bouncing around in their array to map the evolution of electrons in a system of increasing, yet highly controlled, disorder.

    “A good reason why our fidelity was so high is because we’re able to reach complex states in very little time,” Neill explained. The more quickly a system can explore all possible states, the better the prediction of how a system will evolve, he said.

    If all goes smoothly, the world should be seeing a practicable UCSB/Google quantum computer soon. The researchers are eager to put it through its paces, gaining answers to questions that were once accessible only through theory, extrapolation and highly educated guessing — and opening up a whole new level of experiments and research.

    “It’s definitely very exciting,” said Google researcher Pedram Roushan, who led the many-body quantum simulation work published in Science in 2017. They expect their early work to stay close to home, such as research in condensed matter physics and quantum statistical mechanics, but they plan to branch out to other areas, including chemistry and materials, as the technology becomes more refined and accessible.

    “For instance, knowing whether or not a molecule would form a bond or react in some other way with another molecule for some new technology… there are some important problems that you can’t roughly estimate; they really depend on details and very strong computational power,” Roushan said, hinting that a few years down the line they may be able to provide wider access to this computing power. “So you can get an account, log in and explore the quantum world.”

    See the full article here .

    Hello DARKNESS

    UCSB physicists team up with Caltech astronomers to commission the most advanced camera in the world.

    April 16, 2018
    Julie Cohen
    (805) 893-7220
    julie.cohen@ucsb.edu

    3
    The world’s most advanced camera can detect planets around the nearest stars.
    Photo Credit: COURTESY PHOTO

    Somewhere in the vastness of the universe another habitable planet likely exists. And it may not be that far — astronomically speaking — from our own solar system.

    Distinguishing that planet’s light from its star, however, can be problematic. But an international team led by UC Santa Barbara physicist Benjamin Mazin has developed a new instrument to detect planets around the nearest stars. It is the world’s largest and most advanced superconducting camera. The team’s work appears in the journal Publications of the Astronomical Society of the Pacific.

    The group, which includes Dimitri Mawet of the California Institute of Technology and Eugene Serabyn of the Jet Propulsion Laboratory in Pasadena, California, created a device named DARKNESS (the DARK-speckle Near-infrared Energy-resolved Superconducting Spectrophotometer), the first 10,000-pixel integral field spectrograph designed to overcome the limitations of traditional semiconductor detectors. It employs Microwave Kinetic Inductance Detectors that, in conjunction with a large telescope and an adaptive optics system, enable direct imaging of planets around nearby stars.

    “Taking a picture of an exoplanet is extremely challenging because the star is much brighter than the planet, and the planet is very close to the star,” said Mazin, who holds the Worster Chair in Experimental Physics at UCSB.

    Funded by the National Science Foundation, DARKNESS is an attempt to overcome some of the technical barriers to detecting planets. It can take the equivalent of thousands of frames per second without any read noise or dark current, which are among the primary sources of error in other instruments. It also has the ability to determine the wavelength and arrival time of every photon. This time domain information is important for distinguishing a planet from scattered or refracted light called speckles.

    “This technology will lower the contrast floor so that we can detect fainter planets,” Mazin explained. “We hope to approach the photon noise limit, which will give us contrast ratios close to 10-8, allowing us to see planets 100 million times fainter than the star. At those contrast levels, we can see some planets in reflected light, which opens up a whole new domain of planets to explore. The really exciting thing is that this is a technology pathfinder for the next generation of telescopes.”

    Designed for the 200-inch Hale telescope at the Palomar Observatory near San Diego, California, DARKNESS acts as both the science camera and a focal-plane wave-front sensor, quickly measuring the light and then sending a signal back to a rubber mirror that can form into a new shape 2,000 times a second. This process cleans up the atmospheric distortion that causes stars to twinkle by suppressing the starlight and enabling higher contrast ratios between the star and the planet.

    During the past year and a half, the team has employed DARKNESS on four runs at Palomar to work out bugs. The researchers will return in May to take more data on certain planets and to demonstrate their progress in improving the contrast ratio.

    “Our hope is that one day we will be able to build an instrument for the Thirty Meter Telescope planned for Mauna Kea on the island of Hawaii or La Palma,” Mazin said. “With that, we’ll be able to take pictures of planets in the habitable zones of nearby low mass stars and look for life in their atmospheres. That’s the long-term goal and this is an important step toward that.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 10:26 am on September 28, 2017 Permalink | Reply
    Tags: 2-D superlattice, , , Band Gaps Made to Order, Could usher a new generation of light-emitting devices for photonics applications, Each quantum dot acts as a quantum well where electron-hole activity occurs, In the quantum realm precision is even more important, , , , The quantum dot is theoretically an artificial “atom.”, UCSB   

    From UCSB: “Band Gaps, Made to Order” 

    UC Santa Barbara Name bloc
    UC Santa Barbara

    September 25, 2017
    James Badham

    1
    This artist’s representation shows an electron beam (in purple) being used to create a 2D superlattice made up of quantum dots having extraordinary atomic-scale precision and placement.
    Photo Credit: PETER ALLEN

    Control is a constant challenge for materials scientists, who are always seeking the perfect material — and the perfect way of treating it — to induce exactly the right electronic or optical activity required for a given application.

    One key challenge to modulating activity in a semiconductor is controlling its band gap. When a material is excited with energy, say, a light pulse, the wider its band gap, the shorter the wavelength of the light it emits. The narrower the band gap, the longer the wavelength.

    As electronics and the devices that incorporate them — smartphones, laptops and the like — have become smaller and smaller, the semiconductor transistors that power them have shrunk to the point of being not much larger than an atom. They can’t get much smaller. To overcome this limitation, researchers are seeking ways to harness the unique characteristics of nanoscale atomic cluster arrays — known as quantum dot superlattices — for building next generation electronics such as large-scale quantum information systems. In the quantum realm, precision is even more important.

    New research conducted by UC Santa Barbara’s Department of Electrical and Computer Engineering reveals a major advance in precision superlattices materials. The findings by Professor Kaustav Banerjee, his Ph.D. students Xuejun Xie, Jiahao Kang and Wei Cao, postdoctoral fellow Jae Hwan Chu and collaborators at Rice University appear in the journal Nature Scientific Reports.

    Their team’s research uses a focused electron beam to fabricate a large-scale quantum dot superlattice on which each quantum dot has a specific pre-determined size positioned at a precise location on an atomically thin sheet of two-dimensional (2-D) semiconductor molybdenum disulphide (MoS2). When the focused electron beam interacts with the MoS2 monolayer, it turns that area — which is on the order of a nanometer in diameter — from semiconducting to metallic. The quantum dots can be placed less than four nanometers apart, so that they become an artificial crystal — essentially a new 2-D material where the band gap can be specified to order, from 1.8 to 1.4 electron volts (eV).

    This is the first time that scientists have created a large-area 2-D superlattice — nanoscale atomic clusters in an ordered grid — on an atomically thin material on which both the size and location of quantum dots are precisely controlled. The process not only creates several quantum dots, but can also be applied directly to large-scale fabrication of 2-D quantum dot superlattices. “We can, therefore, change the overall properties of the 2-D crystal,” Banerjee said.

    Each quantum dot acts as a quantum well, where electron-hole activity occurs, and all of the dots in the grid are close enough to each other to ensure interactions. The researchers can vary the spacing and size of the dots to vary the band gap, which determines the wavelength of light it emits.

    “Using this technique, we can engineer the band gap to match the application,” Banerjee said. Quantum dot superlattices have been widely investigated for creating materials with tunable band gaps but all were made using “bottom-up” methods in which atoms naturally and spontaneously combine to form a macro-object. But those methods make it inherently difficult to design the lattice structure as desired and, thus, to achieve optimal performance.

    As an example, depending on conditions, combining carbon atoms yields only two results in the bulk (or 3-D) form: graphite or diamond. These cannot be ‘tuned’ and so cannot make anything in between. But when atoms can be precisely positioned, the material can be designed with desired characteristics.

    “Our approach overcomes the problems of randomness and proximity, enabling control of the band gap and all the other characteristics you might want the material to have — with a high level of precision,” Xie said. “This is a new way to make materials, and it will have many uses, particularly in quantum computing and communication applications. The dots on the superlattice are so close to each other that the electrons are coupled, an important requirement for quantum computing.”

    The quantum dot is theoretically an artificial “atom.” The developed technique makes such design and “tuning” possible by enabling top-down control of the size and the position of the artificial atoms at large scale.

    To demonstrate the level of control achieved, the authors produced an image of “UCSB” spelled out in a grid of quantum dots. By using different doses from the electron beam, they were able to cause different areas of the university’s initials to light up at different wavelengths.

    “When you change the dose of the electron beam, you can change the size of the quantum dot in the local region, and once you do that, you can control the band gap of the 2-D material,” Banerjee explained. “If you say you want a band gap of 1.6 eV, I can give it to you. If you want 1.5 eV, I can do that, too, starting with the same material.”

    This demonstration of tunable direct band gap could usher a new generation of light-emitting devices for photonics applications.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 10:29 am on August 23, 2017 Permalink | Reply
    Tags: , NTSs-natural treatment systems, Recovering Runoff, Revolutionize the collection and management of stormwater, UCSB   

    From UCSB: “Recovering Runoff” 

    UC Santa Barbara Name bloc
    UC Santa Barbara

    August 17, 2017
    Shelly Leachman

    1
    Stormwater runoff. Photo Credit: iStock/Resavac

    2
    UCSB doctoral student Marina Feraud, center, is among the researchers involved in a multicampus project to investigate the use of stormwater to combat drought.
    Photo Credit: Matt Perko

    3
    UCSB participants in the project spanning five UC campuses are surveying existing natural treatment systems for possible study. Photo Credit: Matt Perko

    Dumping billions of gallons on California every year, rain is the state’s way out of drought — if only all that water could be captured instead of washing into drains and out to sea.

    An ambitious new collaboration spanning five University of California campuses, including UC Santa Barbara, hopes to do exactly that. The research partnership of UCSB, UC Irvine, UCLA, UC Riverside and UC San Diego aims to revolutionize the collection and management of stormwater — and demonstrate its potential for addressing drought and flood risk. A $1.9 million UC Multicampus Research Programs and Initiatives (MRPI) grant will help get it done.

    The project, “Fighting Drought with Stormwater,” is now underway. Work began in earnest in early August — which happens to be National Water Quality Month. The five Southern California UC campuses will serve as living laboratories for studying natural treatment systems, such as bioswales and biofilters, or rain gardens. The effort is meant to illuminate how well the systems are working now, and how they can be improved in form and function to boost stormwater recovery and bolster water resources.

    “Think about the winter rains in this region — the runoff mainly goes out to the ocean,” said UCSB’s Patricia Holden, a professor in the Bren School of Environmental Science & Management and co-investigator on the grant. “But UCSB and other campuses are increasingly instituting ‘green’ approaches, called natural treatment systems (NTSs), for stormwater management that slow down the runoff, capture it onsite, treat it so that it is less polluting to the ocean, and can recharge shallow groundwater.

    “Many campuses employ NTSs, but how well do they achieve co-benefits of advancing water neutrality, removing pollutants and delivering other ecosystem services?” she added. “How can knowledge — in biogeochemistry, hydrology, ecology and social sciences — assist optimizing designs and NTS management? What incentives are needed, so that stormwater runoff capture and beneficial reuse — at distributed, small scales — becomes more widespread?”

    For UCSB’s part in this multifaceted endeavor, Holden’s team members Dong Li, Marina Feraud and Mitchell Maier are spearheading an investigation into microbial communities in these systems and their impact on nitrogen cycling. By looking into accumulated pollutants in the soil media of NTSs and how they interact with microbes, they hope to ascertain if the level of pollution influences whether NTSs convert nitrate within the system into nitrogen, a harmless gas, or into nitrous oxide, a potent greenhouse gas.

    “The big idea behind the whole project is to advance research on stormwater treatment features that would allow us to capture and treat this water so it can be used as a resource,” said Feraud, a doctoral student. “We hope to increase knowledge of microbial communities in these systems — who’s there and what they’re doing — overlaying that with the level of pollution we might see in the soil media. Ultimately we want to increase overall understanding of these systems, and how design and maintenance choices affect their performance as measured by environmental metrics — in this case the potential to accumulate nitrate or release nitrous oxide. Making more informed choices in how we design and maintain these systems can promote their use and implementation, which we think is very important for treating water and improving water quality, while also allowing for beneficial reuse.”

    The UCSB group, by way of Li, is also bringing a novel line of inquiry to the project: the potential of these systems to reduce or remove disease-causing pathogens from stormwater runoff, through understanding and possibly enhancing natural predator-prey interactions.

    “Sometimes there are human pathogens in stormwater runoff,” said Li, a postdoctoral researcher. “NTSs use bioswales and biofilters to remove these pathogens so that the water can be reclaimed and reused. There are many different pollutants, but human pathogens are particularly important, and we definitely want to reduce their abundances via NTSs. The indigenous microbial ecology may be key to such removal.”

    The many other issues being addressed by this sweeping project include how to effect the removal of chemical pollutants from stormwater; the provision of ecosystem services — and potentially disservices — via these systems; understanding related socioeconomic benefits and drivers; and understanding water budgets in these systems toward achieving water neutrality on campuses and beyond.

    “This is a great demonstration of a collaborative, forward-looking approach to a critical water issue — of both quantity and quality — in Southern California, and one whose discoveries can be informative beyond the campuses,” Holden said. “We aim to use the campuses as testbeds, but produce understanding that can inform sites in surrounding communities.”

    The ultimate, long-range goal?

    Transform the infrastructure of such treatment systems from what today, the researchers say, is a major cause of environmental degradation into a “multifunctional green system that augments urban water supply, protects human and ecosystem health, minimizes flood risk and ensures public safety.”

    Said principal investigator and civil engineer Stanley Grant, of UC Irvine, when the grant was announced, “My hope is that by the end of our project, we will have set the southern UC campuses on a path toward becoming ‘stormwater-neutral,’ by which I mean all rain that falls on the campuses will be captured and used locally. It’s our chance to help the UC maintain its position as a global leader in environmental sustainability research and practice.”

    See the full article here .

    Please help promote STEM in your local schools.

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    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
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