Events List for the Academic Year
Event Time:
Tuesday, March 12, 2024 | 5:30 pm - 7:30 pm
Event Location:
HENN 200
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2024-03-12T17:30:00
2024-03-12T19:30:00
Undergraduate Science Slam
Event Information:
Science Communication skills are key for success in all sciences! Being able to explain a complex scientific idea, or theory clearly to a general audience can show your mastery of a subject, sell your research, or successfully launch a start-up!
PHAS Outreach has partnered with Science Slam Canada to bring this science communication opportunity to our students! Cheer on our physics & astronomy undergrads as they compete in 5-minute challenges for science clarity as they share their mastery with you! If you understand the science...they get points. There will be prizes for audience members and the top slammer.
For undergrad students in Science or Arts - come see what science communication is all about. Cheer on our slammers! Want to learn more about our programs? Stay after the competition to meet students and advisors and learn what we have to offer.
Pizza and drinks included in this evening event! Registration required as space is limited - Sign up today!
Event Location:
HENN 200
Event Time:
Monday, March 11, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 318
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2024-03-11T16:00:00
2024-03-11T17:00:00
Surveying the Sky with Rubin Observatory
Event Information:
Abstract:
Rubin Observatory is on track to start operations of the Legacy Survey of Space and Time (LSST) in fall 2025, setting off a rush of data that will be massive (20TB per night) and nonstop for ten years. The LSST will survey approximately 20,000 square degrees of sky in ugrizy bandpasses, with highly accurate astrometry and photometry, with individual images reaching depths of about 24.5 in r band.
Construction of Rubin has been a long road, starting around 2000, becoming one of the top priorities of the 2010 Astronomy and Astrophysics Decadal Survey recommendations, pushing through COVID -- but commissioning starts this summer and survey operations are on track to start in fall 2025.
The core science drivers for the LSST are constraining dark energy and dark matter, mapping the Milky Way and Local Volume, inventorying the Solar System, and opening new windows on the Transient and Variables Sky. To support these goals, the LSST footprint includes a "Wide Fast Deep" (WFD) region that will receive on the order of 800 visits per pointing, along with additional "mini-survey" coverage of the ecliptic, the galactic plane, and the south celestial pole. The survey plan also includes five Deep Drilling Fields, a few hundred square degrees which receive more than 10x the coverage of the WFD, as well as the possibility for additional "micro-surveys" requiring less than ~1% of the total survey time.
Final (10 year) coadded depths for the 18,000 square degrees in the WFD footprint of the survey will reach approximately 27th magnitude in r band. Photometric redshift measurements are expected to be accurate to 1-3% over a range of 0.2 to 3 in redshift. On the order 20 billion galaxies and 17 billion resolved stars will be reported in the resulting catalogs. Astrometry is expected to be accurate to about 50 mas (10 mas relative precision) with photometric accuracy of 10 mmag.
"Alerts" for each visit, coming from difference imaging, will provide immediate insight into real-time events captured by the survey. On the order of 10 million alerts are expected per night. With multiple measurements per night, typically supplemented by additional visits in the next few days, including information from multiple bandpasses, the alert stream passes a rich source of information about transient and variable phenomenon to the astronomical community. Moving objects will be linked into detections of Solar System objects, with approximately 6 million objects expected to be discovered -- a large fraction of which will be characterized with lightcurve measurements, allowing determination of colors, rotation periods, and phase curves.
Bio:
Lynne Jones is the LSST Performance Scientist, working with Rubin Observatory. She is currently working on the optimization of the LSST survey strategy. She studies small objects throughout the Solar System, with a particular interest in surveys for distant TransNeptunian Objects and lightcurve properties of asteroids. She is currently located in Victoria, BC.
Learn More:
See Lynne's Bio from the Institute for Data Intensive Research in Astrophysics & Cosmology (DiRAC)
Explore the Rubin Observatory
Explore the Legacy Survey of space and time (LSST)
Event Location:
HENN 318
Event Time:
Monday, March 11, 2024 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2024-03-11T11:00:00
2024-03-11T12:00:00
Visualizing Quantum Matter with Cryogenic Electron Microscopy
Event Information:
Abstract:
Quantum-mechanical effects and strong electron-electron interactions give rise to solids with superb electronic properties and a vast potential for future technologies. In many of these strongly interacting materials, electrons self-organize into new spatial patterns that break the symmetry of the underlying crystal. A grand challenge in the field is to understand the nature of these symmetry-breaking states and to overcome their tendency to form inhomogeneous textures at the nanoscale. Towards that goal, atomic-resolution transmission electron microscopy techniques hold immense promise for advancing quantum materials research; however, progress has been hindered by the lack of low-temperature capabilities that are necessary to study quantum systems.
Here I will show vivid atomic-scale visualizations of electronic order in strongly correlated oxides enabled by the development of cryogenic scanning transmission electron microscopy (cryo-STEM). This novel technique enables direct visualizations of (i) the picoscale atomic displacements governing electronic transitions in quantum materials, (ii) the nature and symmetry of charge/orbital order, and (iii) a complex nanoscale landscape involving topological defects, phase competition, and inhomogeneity. Finally, I will describe our recent and unique approach that has enabled cryogenic electron microscopy with liquid helium cooling and atomic resolution. These capabilities pave the way for novel explorations of ultra-low temperature quantum phenomena in the electron microscope.
Bio:
Ismail El Baggari is a Principal Investigator and Fellow at the Rowland Institute at Harvard. He obtained his Ph.D. and M.S. in Physics from Cornell University working with the late Prof. Lena Kourkoutis and a Bachelor of Science in Applied Physics from Yale University. His research focuses on the development of in situ cryogenic electron microscopy for understanding quantum materials and devices.
Event Location:
HENN 318
Event Time:
Friday, March 8, 2024 | 10:30 am - 12:30 pm
Event Location:
BUCH D319 (Buchanan Bldg, 1866 Main Mall)
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2024-03-08T10:30:00
2024-03-08T12:30:00
Control of Molecular Rotation in Superfluid Helium
Event Information:
Abstract:
This work outlines the control of molecular rotation in superfluid helium using nonresonant laser fields. Experiments within bulk superfluid 4He demonstrate control over the rotational frequency and direction of rotation of electronically excited helium dimers (excimers), which are created in nanometre-scale bubbles in the fluid. The excimers rotate for thousands of rotational periods, indicating relatively weak but nonzero coupling to the surrounding helium. Controlling the rotation of molecules therefore serves as a probe of superfluid helium, and its coupling to impurities. The weak coupling is attributed to the fact that helium dimers rotate with rotational energy well above that of the expected excitations of the surrounding helium.
By studying other molecules embedded in helium nanodroplets, we are able to explore the rotation of molecules below, near, and above this energy scale. The influence of strong coupling to the helium becomes extreme when the energies are comparable, severely distorting observed rotational spectra.
Results presented here demonstrate that the rotation of molecules in helium nanodroplets may be controlled in the same manner as molecules in the gas phase. Experiments using an optical centrifuge to attempt to control molecular rotation in helium nanodroplets, and analysis regarding the results, are presented, as well as the first experiments studying rotationally excited nitrogen in helium nanodroplets. Experimental results rotationally exciting nitric oxide dimers in helium nanodroplets present a suitable candidate as a molecule for further study. Alignment of the molecule offers insights to its anisotropic polarizability, and upon rotational excitation, long-lasting rotation exhibits a stronger observable than previously-studied molecules whose rotational energy may be controlled within the desired range.
Event Location:
BUCH D319 (Buchanan Bldg, 1866 Main Mall)
Event Time:
Monday, March 4, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 318
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2024-03-04T16:00:00
2024-03-04T17:00:00
Shedding Light on Electromagnetic Counterparts Across the Gravitational Wave Spectrum
Event Information:
Abstract:
Gravitational wave astronomy is entering a golden era of discovery, and many key science goals of this new frontier rely on 'multi-messenger’ observations that leverage the combination of both 'cosmic messengers' of gravitational waves and light.
I will discuss two recent advances from my research group in understanding the electromagnetic counterparts of gravitational waves across the gravitational wave spectrum. First, I will discuss how the origins of the heaviest elements can be probed, through inferring the abundance pattern of r-process elements produced in binary neutron star mergers from optical spectroscopy of their resultant kilonova explosions. Second, I will discuss how to identify the host galaxies of supermassive black hole binaries that will soon be detected by pulsar timing array experiments, based on their unique morphological and stellar kinematic properties.
Bio:
I am a multi-wavelength astronomer, and my research group is focused primarily on using multi-messenger gravitational wave observations to study kilonova astrophysics, r-process nucleosynthesis, black hole accretion, and cosmology. Most recently, I have become interested in applications of machine learning to computationally-intractable inference problems in astrophysics. For more information, please see the ‘Research Program’ page.
I began my research career as an undergraduate at Columbia University in New York, NY, and did my PhD at the University of Washington in Seattle, WA. For my PhD, I worked primarily on observations of active galactic nuclei variability, but also dabbled in a diverse variety of other areas, including cosmological simulations of galaxy formation, cosmic microwave background secondary anisotropies, and software infrastructure for the Sloan Digital Sky Survey. I then moved to McGill University in Montréal, QC, as a McGill Space Institute Postdoctoral Fellow. There, I began working in the exciting new field of multi-messenger gravitational wave astrophysics, before finally joining the faculty at Bishop’s University in Sherbrooke, QC.
Learn More:
View his website here
Read Bishop's University article: Dr. John Ruan is Appointed Canada Research Chair in Multi-Messenger Astrophysics
See Bishop's University blog on Prestigious scholars here
Event Location:
HENN 318
Event Time:
Monday, March 4, 2024 | 12:30 pm - 1:30 pm
Event Location:
HENN 301
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2024-03-04T12:30:00
2024-03-04T13:30:00
Higgs-Confinement Transitions in QCD from Symmetry Protected Topological Phases
Event Information:
Bio:
Thomas Dumitrescu received a B.A. in Physics and Mathematics from Columbia University in 2008, and a Ph.D. in Physics from Princeton University in 2013, under the supervision of Professor Nathan Seiberg at the Institute for Advanced Study.
Before coming to UCLA, he was a five-year postdoctoral fellow at Harvard University.
Professor Dumitrescu has broad interests in theoretical physics. His research spans many aspects of quantum field theory, including applications to particle and condensed matter physics, as well as supersymmetry, string theory, and mathematical physics. He is particularly interested in developing new theoretical tools for analyzing strongly-coupled quantum field theories, which are beyond the reach of conventional perturbation theory.
Contact:
Thomas Dumitrescu, Assistant Professor, Mani L. Bhaumik Presidential Endowed Term Chair in Theoretical PhysicsTEPOffice: PAB 4-939Phone: 310-825-3162Email: tdumitrescu@physics.ucla.edu
Website: https://www.pa.ucla.edu/faculty-websites/dumitrescu.html
Event Location:
HENN 301
Event Time:
Monday, March 4, 2024 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2024-03-04T11:00:00
2024-03-04T12:00:00
Beyond the Standard Model: Being Precise about the Unknown
Event Information:
Abstract:
The Standard Model of particle physics cannot be the final word on how to understand fundamental particles theoretically. The missing pieces, intriguing patterns and extreme hierarchies of the Standard Model demand explanations, but any new theory must tread a tightrope of increasingly precise measurements.
In this talk I will describe recent work to chart the allowed space of new particles and interactions. By confronting general principles of field theory with the full array of experimental tests, this talk will highlight promising directions to uncover new physics.
Bio:
Sophie Renner is a particle theorist, whose work focuses on possible new particles and interactions beyond those of the Standard Model, and how they may be discovered at experiments. She received her PhD in 2016 from the University of Cambridge, and held postdoctoral research appointments at the University of Mainz, SISSA (Trieste), and CERN. She is currently a lecturer at the University of Glasgow.
Event Location:
HENN 318
Event Time:
Thursday, February 29, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 202
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2024-02-29T16:00:00
2024-02-29T17:00:00
A new vision for the Center for Astrophysics | Harvard & Smithsonian
Event Information:
Abstract:I will present the latest discoveries and developments at the Center for Astrophysics | Harvard & Smithsonian (CfA). Our discoveries cover solar astrophysics, star formation and evolution, galaxy formation & evolution, extrasolar planets, black holes, and cosmology. I will describe the latest ground and space-based technological developments at the CfA, including new space satellites, and compelling new instrumentation for current and future ground-based telescopes in the optical, infrared, IR, and X-rays, as well as for climate science. I will discuss our challenges with Petabyte scale datasets and the application of AI to astronomical problems. Finally, I will provide an overview of the diversity, inclusion and culture initiatives that are being implemented at the CfA, using evidence-based studies from the literature.
Bio:
Lisa Kewley is Director of the Center for Astrophysics | Harvard & Smithsonian. She is Director of the Smithsonian Astrophysical Observatory, Director of the Harvard College Observatory, and Professor of astrophysics at the Harvard Department of Astronomy.
Kewley obtained her PhD in 2002 from the Australian National University on the connection between star-formation and supermassive black holes in galaxies. She was a Harvard-Smithsonian Center for Astrophysics Fellow and a NASA Hubble Fellow. Her awards include the 2006 American Astronomical Society Annie Jump Cannon Award, the 2008 American Astronomical Society Newton Lacy Pierce Prize, and the 2020 US National Academy of Science James Craig Watson Medal. In 2014, Kewley was elected Fellow of the Australian Academy of Science “for her fundamental advances in understanding of the history of the universe, particularly star and galaxy formation”, and in 2015, Kewley was awarded an ARC Laureate Fellowship, Australia’s top fellowship to support excellence in research. In 2020, Kewley was awarded the US National Academy of Sciences James Craig Watson Medal, in 2021 she was elected to the US National Academy of Sciences, and in 2022 she was elected to the American Academy of Arts and Sciences. From 2017-2022, Kewley implemented her scientific vision through her Australian Research Council Centre of Excellence in All-Sky Astrophysics in 3D (ASTRO 3D).
In July 2022, Kewley became Director of the Center for Astrophysics | Harvard & Smithsonian. At the CfA, she is implementing an ambitious new vision for the next generation space and ground-based telescopes, petabyte-scale data handling, new diversity and inclusion initiatives, and nation-wide education and outreach programs.
Learn More:
See her webpage at the Center for Astrophysics
View her bio at the Smithsonian
Read her wikipedia page
Event Location:
HENN 202
Event Time:
Thursday, February 29, 2024 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2024-02-29T11:00:00
2024-02-29T12:00:00
Observation of Pines' Demon in Sr2RuO4
Event Information:
Abstract:Electrons confined in a material exhibit rich quantum behavior with no counterpart in free space. In particular, electron-electron interactions give rise to quantized collective particles which we can use to fundamentally understand the properties of materials. For metals, the primary collective mode of electrons is the plasmon - a quantized excitation where all the electrons move together in synchrony. In 1956, David Pines predicted another particle, known as the "demon", inside multiband metals where electrons of different "flavors" move out-of-phase with each other. For over 66 years, the demon remained undetected because demons are both gapless (i.e. massless) and do not couple to light. Nevertheless, demons are predicted to be responsible for diverse phenomena ranging from phase transitions in mixed-valence materials, "soundarons" in Weyl semimetals, and superconductivity in, for example, metal hydrides. In this talk, I will present evidence for the demon in Sr2RuO4 using the newly developed technique of Momentum-resolved Electron Energy-Loss Spectroscopy (M-EELS). Our study confirms the existence of Pines' demon and indicates that demons may be a pervasive feature of multiband metals. Finally, I will discuss emerging experimental efforts for discovering new collective particles in quantum materials that have escaped experimental identification.
Bio:Ali Husain received his B.S. in Physics from the University of California, Berkeley in 2014. In 2020, he completed his Ph.D at the University of Illinois at Urbana-Champaign in condensed matter physics focusing on the problem of charge dynamics in so-called "strange" metals. From 2020-2022, Ali was the SBQMI Postdoctoral Prize Fellow at the University of British Columbia working with George Sawatzky and Steven Dierker to develop new methods for studying quantum materials using electron microscopy and spectroscopy. Since 2022, Ali has been an AMO research scientist at Quantinuum building next-generation trapped-ion quantum computers.
Event Location:
HENN 318
Event Time:
Thursday, February 29, 2024 | 9:45 am - 10:45 am
Event Location:
BRIM 311
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2024-02-29T09:45:00
2024-02-29T10:45:00
Quantum sensing in the solid-state: from one spin to many spins
Event Information:
Abstract: Sensors that leverage quantum phenomena to measure physical quantities harbor many attractive features beyond classical sensors. Solid-state quantum sensors, with the nitrogen-vacancy (NV) center in diamond a forefront technology, are particularly attractive for their compatibility with biological and condensed matter systems, offering ultra-high spatial resolution and sensitivity over a wide temperature range, while being quantitative and non-invasive. Here I first present our group’s work on NV-center-based scanned probe imaging of electron flow patterns in graphene, revealing the presence of hydrodynamic electron flow. A frontier of quantum sensing is the utilization of entangled quantum sensors for metrological advantage, a goal not yet realized in the solid-state. I also discuss our group’s progress towards realizing novel many-body states of entangled spins, both diamond-based qubits and novel chemically-assembled molecular spin systems.
Speaker Bio: Ania Bleszynski Jayich is a professor of physics at the University of California Santa Barbara, where she holds the Bruker Endowed Chair for Science and Engineering, the Elings Endowed Chair for Quantum Science, and is co-director of the Quantum Foundry, an NSF Q-AMASE-I center. Her research interests include quantum assisted sensing and imaging on the nanoscale, spin-coupled optomechanics, and hybrid quantum systems for sensing and quantum information. Before coming to UCSB, Ania was a postdoctoral researcher at Yale University, and received her PhD in physics from Harvard in 2006 and a B.S. in physics and mathematical and computational science from Stanford in 2000.
Event Location:
BRIM 311
Event Time:
Tuesday, February 27, 2024 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2024-02-27T11:00:00
2024-02-27T12:00:00
New frontiers in error correction and many-body physics: non-equilibrium quantum matter and non-Euclidean geometries
Event Information:
Abstract:
Error correction is a key ingredient towards realizing scalable quantum computation and is also of fundamental interest due to its close connection to exotic quantum phases of matter. In my talk, I will discuss some recent results at the interface of quantum error correction and quantum many-body physics. In the main part of the talk, I will discuss the problem of realizing error correction in a fully local way, without the need for non-local communication between a classical processor and the quantum device. This fits into the broader problem of classifying quantum phases of matter in dissipative open systems. I will formulate conditions for the stability of phases in open systems, putting it on a footing similar to the analysis of quantum phases of matter at zero temperature. In the last part of the talk, I will briefly discuss recent breakthroughs in the field of quantum low-density parity check (LDPC) codes, which live on highly expanding non-Euclidean graph geometries, and describe how they can be understood in the language of gauge theories, familiar from high energy and condensed matter physics.
[1] Defining stable phases of open quantum systems, TR, Sarang Gopalakrishnan, Curt von Keyserlingk, arXiv 2308.15495
[2] The physics of (good) LDPC codes I: Gauging and dualities, TR, Vedika Khemani, arXiv 2310.16032
Bio:
Tibor Rakovszky is a Bloch Postdoctoral Fellow in Quantum Science and Engineering at Stanford University. Previously, he completed his PhD at the Technical University of Munich in 2020. His PhD work focused on dynamics in interacting quantum systems, combining ideas from quantum information theory and many-body physics to understand the scrambling of quantum information and its relationship to thermalization and transport in closed quantum systems. He subsequently extended these studies to include the effects of local measurements on quantum dynamics. His more recent interests are at the intersection of quantum error correction and many-body physics. In particular, he is interested in the classification of quantum phases of matter in novel regimes and the use of such phases for storing and manipulating quantum information.
Event Location:
HENN 318
Event Time:
Friday, February 23, 2024 | 9:30 am - 11:30 am
Event Location:
Henn 318
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2024-02-23T09:30:00
2024-02-23T11:30:00
Atom-Atom, Atom-molecule and molecule-molecule collisions at ultra-cold and room temperature
Event Information:
Abstract:
This thesis describes experiments with magnetically and optically trapped ultra-cold gases of 6Li and 85,87Rb atoms. We describe three distinct areas of investigation, with a common theme of probing collisions: the production of deeply bound 6Li2 dimers and a study of their reactive collisions, the use of ultra-cold atoms as a pressure sensor by measuring the loss rate due to collisions with background gases at room temperature, and progress towards investigating heteronuclear collisional resonances between ultra-cold 6Li and 85,87Rb.
We report on the production of deeply bound triplet a(13Σ+u ) 6Li2 molecules in a single quantum state by stimulated Raman adiabatic passage. The ensemble lifetimes for these molecules were found to be limited by dimer- dimer collisions whose rate depends on the ro-vibrational state of the collision partners. The loss rate observed follows a universal prediction for the |v = 0, 5, 8; N = 0, 2⟩ states, and remarkably, a sub-universal rate for the |v = 9; N = 0⟩ state. We find that molecules in the ground state of the triplet potential are also collisionally unstable, consistent with theoretical predictions that molecules in any of the triplet levels are chemically unstable and decay due to a barrier-less trimer formation process.
We also report on a comparative measurement of the cross section for trap loss inducing collisions of 6Li and 87Rb atoms when exposed to various common background gases found in ultra-high vacuum (UHV) environments, including H2, He, Ne, N2, Ar, Kr and Xe. Ultra-cold 6Li and 85,87Rb atoms are used as a sensitive probe of the background gas pressure, with the quantity ⟨σlossv⟩ essential for converting the observed loss rate due to background gas collisions into a pressure measurement.
Finally, we discuss the production of ultra-cold mixtures of 6Li and 85,87Rb atoms, and the progress towards investigating heteronuclear Feshbach resonances. The Feshbach resonances allow us to tune the interaction strength, which is an essential tool for investigating few and many-body physics in these systems. We discuss the particular example of the Efimov effect, which would be a natural topic of study following our investigating of the Feshbach resonance spectrum.
Event Location:
Henn 318
Event Time:
Thursday, February 22, 2024 | 1:00 pm - 2:00 pm
Event Location:
BRIM 311
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2024-02-22T13:00:00
2024-02-22T14:00:00
Electrons in twisted layers: design, surprise, and a new set of eyes
Event Information:
Abstract: When two atomically-thin layers of a material are stacked one atop each other, with a relative twist angle between them, properties can emerge that bear little resemblance to the behavior of the individual layers. Though much can be predicted and designed about such structures, I will share two vignettes about how my students aimed for a particular behavior but found something quite different. The first led to the discovery of the first experimentally-known “orbital magnet”, a ferromagnet in which the tiny microscopic magnets that align with each other are not electron spins but tiny circulating current loops. The second surprise was observation of resistance that skyrocketed with the application of a magnetic field, along with other striking electronic properties — this one took years to figure out, but we’ve recently explained it.
Each of these two surprises turned out to be caused by a structural feature of the layered stack which had not previously been considered important. Finally, I’ll describe a refined approach to stacking and a newly-developed technique for mapping the structure of twisted layers, which together might help us get more repeatable control of structure and thus electronic properties in such twisted systems.
Event Location:
BRIM 311
Event Time:
Thursday, February 22, 2024 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2024-02-22T11:00:00
2024-02-22T12:00:00
Sculpting quantum many-body states and quantum error correcting codes with measurements
Event Information:
Abstract:
Quantum mechanics exhibits a stark dichotomy between unitary time-evolution and measurement. These aspects are further contrasted by the fact that traditional many-body quantum theory is developed solely based on unitary aspects. In this talk, I will explore two fruitful synergies that emerge from the interplay between many-body quantum physics and the non-equilibrium quantum dynamics that arises from measurements. First, I will show how measurements can be used to circumvent fundamental constraints imposed by unitary dynamics and efficiently prepare a large class of topological phases of matter. In addition to discovering a new hierarchy of many-body quantum states unseen in the unitary setup and a surprising connection to the unsolvability of the quintic polynomial, our studies also yield practical protocols for quantum processors that led to the first unambiguous observation of non-Abelian anyons. Second, I will show how insights from topological phases of matter can in turn contribute to a physical understanding of the newly introduced "Floquet" quantum error correcting codes, featuring a schedule of anticommuting measurements. I will demonstrate that periodicity in time is in fact not required, unlocking a more general construction of "dynamic codes" that are capable of not just error correction, but also fault-tolerant quantum computation.
Bio:
Nat Tantivasadakarn obtained his undergraduate degree from UC Berkeley, his Master's from the Perimeter Institute for Theoretical Physics and his Ph.D. from Harvard University. He is currently a Burke postdoctoral fellow at Caltech. His research interests explore the interplay between topological phases of matter, quantum error correction and computation, non-equilibrium quantum dynamics and generalized symmetries.
Event Location:
HENN 318
Event Time:
Thursday, February 15, 2024 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2024-02-15T11:00:00
2024-02-15T12:00:00
Long-lived superconducting quantum circuits toward fault-tolerant quantum computing
Event Information:
Abstract:Superconducting quantum circuits represent fully engineerable quantum systems, positioning them as a leading platform for large-scale quantum computing. Despite recent milestones like surface code demonstrations and achieving quantum supremacy, scaling up to millions of qubits for fault-tolerant operations remains a significant challenge. Our research focuses on enhancing qubit lifetimes within superconducting quantum circuits to reduce resource requirements significantly. We pursue two primary strategies: Firstly, we investigate the loss mechanisms affecting state-of-the-art superconducting qubit lifetimes. By careful optimization of the fabrication process, sample packaging, and cryogenic wiring, we demonstrate long-lived superconducting qubits, recording one of the best qubit lifetimes (> 0.5 milliseconds). By leveraging these long-lived qubits as quantum sensors, we identify a new loss mechanism attributed to mechanical shocks from the pulse tube cooler of a dilution refrigerator. This discovery suggests new error mitigation strategies by isolating superconducting qubits from mechanical environments. Secondly, we introduce mechanical oscillators based on circuit optomechanics, facilitated by a novel nanofabrication process involving silicon-etched trenches. This breakthrough enables the realization of ultra-coherent and highly scalable systems (> 10 milliseconds and > 20 modes), leading to the first demonstrations of tracking the thermalization of a mechanical squeezed state and engineering topological optomechanical lattices. These advancements not only bring insights into decoherence mechanisms but also pave the way for scalable fault-tolerant quantum computing.
Event Location:
HENN 318
Event Time:
Thursday, February 15, 2024 | 9:45 am - 10:45 am
Event Location:
BRIM 311
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2024-02-15T09:45:00
2024-02-15T10:45:00
Frustrated Quantum Devices: understanding how correlations, complex order and boundary states manifest in novel material functionalities
Event Information:
Abstract: Materials at the boundary of critical phase transitions are of significant fundamental interest, not least due because of their connection to unconventional superconductivity and quantum magnetism. One characteristic of such systems is the presence of coupled order parameters that underlie these phase transitions. Here, we explore how this coupling manifests in the response of these materials when driven out of equilibrium by applied currents. We demonstrate how magnetic and charge textures can be electrically manipulated, suggesting possible applications for exotic materials in spintronics technologies.
Event Location:
BRIM 311
Event Time:
Monday, February 12, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 318
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2024-02-12T16:00:00
2024-02-12T17:00:00
A machine learning lens on galaxy mergers in the nearby Universe
Event Information:
Abstract:
Merger events are thought to interrupt the otherwise gradual evolution of galaxies with short periods of intense change, simultaneously transforming galaxy morphologies, fueling bursts of star formation, and giving rise to high accretion rates onto central supermassive black holes. In this talk, I will demonstrate how machine vision techniques have fundamentally changed the way mergers are identified and studied and highlight new observational results that constrain the influence of mergers on the evolutionary trajectory of galaxies. While some of these results highlight the elegance of the current paradigm for hierarchical galaxy growth, others point to complications brought on by the multi-wavelength diversity of galaxies, stars, and supermassive black holes in the Universe.
Bio:
Bobby Bickley is an astronomy Ph.D. candidate at the University of Victoria (unceded Lekwungen territory, Victoria BC). He also holds a B.Sc. in mechanical engineering from the University of Connecticut. Bobby’s research interests are galaxy evolution, galaxy mergers, supermassive black hole & galaxy co-evolution, and the application of machine learning techniques to problems in astronomy.
Event Location:
HENN 318
Event Time:
Thursday, February 8, 2024 | 2:00 pm - 3:00 pm
Event Location:
TRIUMF Auditorium
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2024-02-08T14:00:00
2024-02-08T15:00:00
Megajoule Fusion Yields at the National Ignition Facility (shared with UBC)
Event Information:
Abstract:
With 192 laser beams delivering over 2 megajoules of energy to target, the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is the world's most energetic laser system and, for the first time in a controlled laboratory setting, has demonstrated fusion ignition and target gain greater than 1. The NIF generates ignition conditions by precisely firing the lasers onto a target comprising a centimeter-tall cylinder inside of which is a millimeter-scale spherical shell filled with deuterium-tritium fuel. The fuel highly compresses, fusing the deuterium and tritium to release helium and large quantities of neutrons and energy. A series of advances over the course of decades were required to reach this stage - laser optical components, target fabrication precision, and implosion design. Building from here, the momentous demonstration of reproducible ignition paves the way for a new category of ignition science experiments as well as a broad array of materials and nuclear science studies within a novel regime of high energy density physics.
Bio:
Berzak Hopkins is a design physicist at Lawrence Livermore National Laboratory, focusing on inertial confinement fusion experiments on the National Ignition Facility (NIF). She has already has made a mark at NIF as part of the team that performed the first shots to show more energy coming out of the hydrogen fuel than was deposited in it. While still short of ignition – when the energy out is greater than that needed to spark the fusion reaction – it’s a big step forward.
Laura also runs a website designed to connect the public to science research. “My goals continue to be to pursue what challenges me and what I feel passionate about, both in the arena of scientific research as well as in science policy and politics”.
Learn More:
See Laura's bio from the Lawrence Livermore National Laboratory website
Review her research here
Event Location:
TRIUMF Auditorium
Event Time:
Thursday, February 8, 2024 | 10:00 am - 11:00 am
Event Location:
BRIM 311
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2024-02-08T10:00:00
2024-02-08T11:00:00
Ultrafast optoelectronic circuits
Event Information:
Abstract: Ultrafast optoelectronic circuits offer new opportunities for investigating and controlling the electrical responses of microstructured quantum materials and heterostructures at femtosecond timescales and THz frequencies. Based on metal waveguides and laser-triggered photoconductive switches, these chip-scale circuits can be interfaced to quantum materials to directly probe the ultrafast flow of electrical currents or perform near-field THz spectroscopy on length scales orders of magnitude smaller than the diffraction limit.
In this talk, I will present on my group’s activities using these circuits to study the electrical transport properties of quantum materials driven out of equilibrium by femtosecond laser pulses [1]. In monolayer graphene, we observe an anomalous Hall effect induced by circularly polarized light in the absence of an applied magnetic field [2]. The dependence of the effect on a gate potential used to tune the Fermi level reveals multiple features that reflect the formation of a photon-dressed, or “Floquet-engineered”, topological band structure. The results are a critical first step towards realizing and controlling light-induced topological edge states. I will also discuss our recent results on the Weyl semimetal Td-MoTe2, where we observe rectified photocurrents that scale linearly with the applied laser field. This scaling violates the perturbative description of nonlinear optics/transport, but can be explained by the formation of a photon-dressed magnetic Weyl semimetal state.
In the second part of my talk, I will present on my group’s efforts in using femtosecond voltage pulses generated on-chip to probe and manipulate gate-tunable van der Waals heterostructures embedded in plasmonic cavities. We perform near-field time-domain THz spectroscopy on these cavities to study the light-matter hybridization. We observe coherent plasmon cavity modes that can be tuned from the weak to ultrastrong coupling regimes with electrostatic gating and cavity geometry. These techniques, which we are extending to mK temperatures and strong magnetic fields, could be used to investigate and control a wide range of topological and strongly correlated phenomena in microstructured quantum materials and heterostructures that fall on the THz/meV energy scale.
Event Location:
BRIM 311
Event Time:
Wednesday, February 7, 2024 | 3:00 pm - 4:00 pm
Event Location:
Henn 318
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2024-02-07T15:00:00
2024-02-07T16:00:00
FPGA-based Data Acquisition and Instrumentation in Astrophysics Experiments
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Abstract:
The recent advancement of Field-Programmable-Gate-Array (FPGA) technology has made them more appealing for experimental astrophysics. These experiments typically require fast and parallel processing of huge amount of data with customizable computation in terms of signal-processing chain and bit depth. Today, FPGAs come with a variety of high-speed Analog-to-Digital data converters (ADCs), high-speed serial transceivers and configurable interfaces for standard peripherals: DDR4, PCIe, 10G Ethernet. The integration of these blocks and the programmable fabric on the same chip provides lower power consumption, higher integration (or smaller footprint) which in turn helps scalability and flexibility needed for astrophysics experiments. Here, we present an example implementation of a 2-channel Spectrometer readout on Xilinx RFSoC 4x2 platform.
Event Location:
Henn 318