Eric Sembrat's Test Bonanza

Abstract

The management of dissipation and heat flows in quantum nanoelectronic devices is becoming of growing importance, in particular in view of preservingcoherence in quantum information processing applications. Single-quantum-dot junctions, which involve electron transport through a single quantum level, are a key element for quantum electronics. We study the thermoelectric and thermal transport properties of such devices. We demonstrate that the gate potential canbe used to modulate the heat carried by electrons across a single quantum level [1], which remains however significantly below the naive expectation from the Wiedemann-Franz prediction [2]. Although a general theory for heat transport through a quantum dot junction, accounting for on-site interactions, is still lacking, the heat transport data are well captured at the conductance resonances by non-interacting scattering theory. Eventually, going beyond quasi-equilibrium conditions, the potential of time-resolved thermometry for the calorimetric detection of out-of-equilibrium processes and fluctuations in quantum devices will be discussed.

[1] B. Dutta et al., Phys. Rev. Lett. 125, 237701 (2020).

[2] D. Majidi et al., Nano Lett. 22, 630 (2022).

Bio: C. Winkelmann obtained his PhD in 2004 from the University of Grenoble. He is now an Associate Professor of Physics at the Grenoble Institute of Technology. His research focuses on the electronic properties of quantum materials and devices, in particular related to mesoscopic superconductivity, low dimensionality and thermal properties in the quantum regime.

Abstract:

Short pulse (<10 ps), high-intensity (>1018 W/cm2) laser systems can be used to generate and probe extremely high energy and density conditions of matter. The plasmas produced by these high intensity laser systems can act as compact radiation sources, can emulate astrophysical phenomena like supernova and centers of giant planets, and even allow access to fusion regimes. Besides fundamental plasma physics, these ultraintense laser-matter interactions also lend themselves to impactful scientific applications, including renewable energy and state-of-the-art medical techniques.

A continuing fundamental need in the field of laser-driven High Energy Density (HED) and plasma physics is the accurate and precise spatial and temporal characterization of the laser pulse, which would provide valuable insight into the foundational physics that drive these interactions. Laser-plasma interactions are complex, rapidly evolving, and highly sensitive to shot-to-shot variations in laser parameters, such as laser peak intensity, pulse duration, pre-pulse, and focal spot, and/or thermal instabilities. Even under nominally identical laser conditions, small variations can drastically influence outcomes. However, in typical HED experiments currently, the complexity of the 4-D laser electric field E(x,y,z,t) can mean that the wavefront is not often characterized, or that it is characterized in a surrogate setup or surrogate shot. To accurately understand these interactions, on-shot experimental techniques must be established and implemented. I will discuss the development of a single-frame laser characterization diagnostic for novel use on high-intensity, low repetition rate laser systems, its adaptation to high-repetition rate (>Hz) laser systems, its use in diagnosing and optimizing an ultraintense laser system, and its role in developing a more complete understanding of the underlying laser-plasma interaction physics. Breakthroughs in these measurement capabilities can unlock an entirely new regime of experimental measurement, deliver a novel capacity to determine and assess pivotal factors that limit more precise control of laser-driven radiation sources, and serve as a necessary tool to improve laser-plasma interaction predictive capability.

Abstract: LIGO’s detections of gravitational waves from binary mergers made history and continue to yield insights into gravity and extreme matter. What other gravitational wave signals will be detected, from LIGO to Cosmic Explorer? What physics and astrophysics will we learn from them, especially in tandem with other astronomical messengers? After summarizing some highlights of my past contributions to searches for short lived signals such as binary mergers and star quakes, I will focus on continuous gravitational waves from spinning neutron stars as an exciting frontier for the future.

Bio: Ben Owen got his BS from Sonoma State University and his PhD from Caltech, where he helped lay the foundations of gravitational wave data analysis and won the Clauser Thesis Prize for showing that the “r-mode instability” of neutron stars could generate gravitational waves under realistic conditions. As a postdoc at the Albert Einstein Institute in Golm and the University of Wisconsin-Milwaukee, and as faculty at Penn State and Texas Tech, he contributed to searches for a wide variety of gravitational wave signals, mostly guided by electromagnetic observations, and was elected APS Fellow for his contributions to neutron star gravitational wave astronomy. He served the LIGO Scientific Collaboration as review chair of the burst data analysis group and astronomy liaison for the continuous waves group, and was director of the Penn State Center for Gravitational Wave Physics. He is a member of the Cosmic Explorer consortium.

Abstract: Harnessing the behavior of complex systems is at the heart of quantum technologies. Precisely engineered ultracold gases are emerging as a powerful tool for this task. In this talk I will explain how ultracold strontium atoms trapped by light can be used to create optical lattice clocks – the most precise timekeepers ever imagined. I am going to explain why these clocks are not only fascinating, but of crucial importance since they can help us to answer cutting-edge questions about complex many-body phenomena and magnetism, to unravel big mysteries of our universe and to build the next generation of quantum technologies.

Bio: Professor Ana María Rey is a Fellow of JILA, a NIST Fellow, and a Professor Adjoint at the Department of Physics at the University of Colorado Boulder. She received a B.S. from Universidad de los Andes, in Bogota-Colombia, and a Ph.D. from the University of Maryland. Between 2005 and 2008, she was a postdoctoral fellow at the Harvard Smithsonian Center for Astrophysics, after which she joined the faculty at JILA and UC Boulder. Rey’s research interests are in the scientific interface between atomic, molecular and optical physics, condensed matter physics and quantum information science. She has been the recipient of various awards, including the DAMOP Thesis Prize (2005), a MacArthur Foundation Fellowship (2013), the Presidential Early Career Award for Scientists and Engineers (2013), the Maria Goeppert Mayer Award of the American Physical Society (2014), and the Blavatnik National Awards for Young Scientists (2019). Rey is also a Fellow of the American Physical Society.

Abstract: We have developed autonomous robots with mutable diploid genes, capable of both death, rebirth and breeding, which move over resource landscapes, landscapes which the robots locally alter, and which can also be changed externally, as in drug therapy. We do this to explore biological evolution, a complex, non-linear process. We map the equilibrium surviving local density of the robots onto a multi-dimensional abstract “success landscape”, success being defined as the collective surviving number of robots after resource stress, mutations, breeding and death. We show it is generally necessary for robot success on an externally and self-modified resource stress landscape to require the exchange of genes between the robots in addition to mutations. Although the map from resources and genetics to success is quite complex, non-linear and multidimensional, our simplified robot evolving swarm illustrates basic rules for success under highly dynamic and spatially complex stress conditions which could be applied to a deeper understanding of controlling intractable diseases via stress dynamics. But they won’t build the car you ordered and are waiting for.

Bio: Professor Robert H. Austin received his B.A. in Physics from Hope College in Holland, Michigan and his Ph.D. in Physics from the University of Illinois Champaign-Urbana in 1975. He did a post-doc at the Max Planck Institute for Biophysical Chemistry from 1976–1979 and has been with the Department of Physics of Princeton University from 1979 to the present, achieving the rank of Professor of Physics in 1989.

He is a Fellow of the American Physical Society, a Fellow of the American Association for the Advancement of Science, and was elected a member of the National Academy of Sciences USA. He has served as a President of the Division of Biological Physics of the American Physical Society, and is the present Chair of the U.S. Liaison Committee of the International Union of Pure and Applied Physics. He has served as the biological physics editor for Physical Review Letters, serves on numerous review panels for National Institutes of Health (NIH), National Science Foundation (NSF), the Burroughs Welcome Fund and National Institute of Standards and Technology (NIST), and is the Editor of the Virtual Journal of Biological Physics. He won the 2005 Edgar Lilienfeld Prize of the American Physical Society, was elected in 2008 as a Fellow, American Association of Arts and Sciences, and won the 2014 Delbruck Prize of the American Physical Society.

Abstract: Effects of spin-orbit interactions in condensed matter are an important and rapidly evolving topic. A sea change occurred with the discovery of spin-orbit interactions in graphene by Mele and Kane, which has led to the exciting new field of physics addressing a rare interplay between spin-orbit and Coulomb interactions in condensed matter. I will describe an entirely new hierarchy of energy scales inherent in 4d- and 5d-electron based oxides and its unique consequences, highlighting discrepancies between experimental confirmation and theoretical proposals that address superconducting, topological and quantum spin liquid phases in iridates.

I will then present our recent discoveries of novel quantum phenomena in iridates and ruthenates and conclude by venturing a perspective for research on spin-orbit-coupled oxides [1,2].

References: 1. Physics of Spin-Orbit-Coupled Oxides, Gang Cao and Lance E. De Long, Oxford University Press; Oxford, 2021 2. The Challenge of Spin-Orbit-Tuned Ground States in Iridates: A Key Issues Review, Gang Cao and Pedro Schlottmann, Reports on Progress in Physics, 81 042502 (2018)

Bio: Gang Cao is professor of physics at University of Colorado at Boulder. Prior to the current appointment, he was Jack and Linda Gill Eminent Professor at University of Kentucky, and staff scientist at National High Magnetic Field Laboratory, respectively. He received his Ph.D. in Physics under direction of Prof. Jack E. Crow at Temple University in Philadelphia in 1993. His research interests focus on discovery, synthesis, and study of 4d and 5d transition metal materials and high-field, high-pressure and low-temperature properties of these materials. Prof. Cao was elected Fellow of the American Physical Society (DCMP) in 2009.

Abstract: In recent years, the number of objects in space has grown rapidly, and this growth is projected to continue to accelerate over the next decade. There has also been increased military activity in space, including rendezvous and proximity operations and debris-creating anti-satellite tests. These trends pose risks to the sustainability and security of the space environment – risks that have the potential to negatively affect all space users, including those in the astronomy and astrophysics communities. In many cases, addressing these issues requires international coordination and cooperation.

This talk reviews some of the current challenges and risks to the space environment and discusses ongoing efforts to develop international policy solutions.

Bio: Mariel Borowitz is an Associate Professor in the Sam Nunn School of International Affairs at Georgia Tech. Her research deals with international space policy issues, including international cooperation in Earth observing satellites and satellite data sharing policies. She also focuses on strategy and developments in space security and space situational awareness. Dr. Borowitz earned a PhD in Public Policy at the University of Maryland and a Masters degree in International Science and Technology Policy from the George Washington University. She has a Bachelor of Science degree in Aerospace Engineering from the Massachusetts Institute of Technology. Dr. Borowitz completed a detail as a policy analyst for the Science Mission Directorate at NASA Headquarters in Washington, DC from 2016 to 2018. Her book, “Open Space: The Global Effort for Open Access to Environmental Satellite Data,” was published by MIT Press in 2017.

Abstract: Gravitational wave cosmology with galaxy surveys

The synergy between gravitational wave (GW) experiments and large galaxy surveys such as the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI) is most prominent in the standard siren method, which has already enabled several measurements of the Hubble Constant. A standard siren analysis was performed using the only GW event with an electromagnetic counterpart, GW170817, for the first time. We have later extended the analysis to compact object binary merger events without counterpart using DES and DESI galaxy catalogs, for which I will present the latest results. These measurements have the potential to shed light on the Hubble constant tension in the coming years. In the last part of the talk, I will present some interesting possibilities for the formation of the most massive binary black hole mergers detected so far which are related to galaxies’ central black holes, in particular those in dwarf galaxies and Active Galactic Nuclei.

Bio: Antonella Palmese is an Einstein Fellow at the University of California, Berkeley, working mostly on the Dark Energy Spectroscopic Instrument (DESI) and multi-messenger observations of gravitational wave events. She got her PhD at University College London in 2018, where she worked on the Dark Energy Survey (DES). Before moving to Berkeley, Antonella was a postdoc at the Fermi National Accelerator Laboratory, as well as an associate fellow at the Kavli Institute for Cosmological Physics, at the University of Chicago. She currently is the co-chair of the DESI Transients and Low-z Cosmology Working Group and of the DES Galaxy Evolution and Quasars Working Group. She is interested in combining optical and gravitational wave data to measure cosmological parameters and understand the origin of gravitational wave sources.

Abstract: Since the first direct observation of gravitational waves seven years ago by the LIGO detectors, this new field of astrophysics has provided us with unparalleled insights into the most extreme events in the Universe and has allowed us to test the nature of gravitation itself. And with now nearly 100 individual transient gravitational-wave sources detected, the possibilities for these tests to be applied to an entire population of observations can enable detailed studies into high-precision astrophysics as well as probes of fundamental physics not accessible through other means.

In order to achieve these insights, we require the tools and methods used to analyze the gravitational waves to be powerful, fast and robust enough to handle both the rate at which observations are made as well as being sufficiently trustworthy to not corrupt or bias the delicate measurements. As the gravitational wave observatories are improved over the coming few years, both the rate and fidelity of observations are expected to increase to a point where the current analysis tools will no longer be able to keep up.

In this talk I will be presenting my recent work aiming to prepare these analyses for the observations of the future, and provide examples of what advances in both physics and astrophysics such observations will bring.

Short Bio: Carl got his PhD in Gravitational Wave Astrophysics from the University of Birmingham in 2016 and, following a postdoctoral fellowship at the Canadian Institute for Theoretical Astrophysics, is now a postdoctoral associate at the MIT Kavli Institute for Astrophysics and Space Research. His research interests includes the development of methods for inference of the astrophysical origin of gravitational wave transient signals, using this inference to better understand the behavior of the most extreme astrophysical objects and processes in the Universe and to learn more about the fundamental physics governing the formation and evolution of the populations of black holes and neutron stars we can observe both today and in the future.

Abstract: Exploring and understanding new quantum materials with advanced properties tied to their nontrivial magnetic and electronic structures has been a central focus of modern condensed matter physics over the past few decades. The success of these efforts relies simultaneously on advances in theory, material synthesis, and development of new, sensitive metrology tools to characterize the key material properties at the nanoscale. Nitrogen-vacancy (NV) centers, optically active atomic spin defects in diamond, are naturally relevant in this context due to their single-spin sensitivity, excellent quantum coherence, unprecedented spatial resolution, and remarkable functionality over a broad temperature range. Serving as a local probe of multiple degrees of freedom, NV centers are ideally posed to investigate the fundamental correlations between microscopic magnetic textures and underlying charge, thermal transport properties of quantum materials. In this talk, I will present our recent work on using NV centers to perform quantum sensing and imaging of emergent condensed matter systems. Specifically, we utilized NV wide-field method to probe the exotic spin properties of intrinsic topological magnets and antiferromagnetic Weyl semimetals, revealing the fundamental physics underlying the diffusive spin transport, magnetic phase transitions, spin fluctuations, and spin-current driven magnetic switching behaviors at the nanoscale.

Our results demonstrate the unique capabilities of NV centers in accessing the local information of magnetic order and dynamics in these emergent material systems and suggest new opportunities for investigating the interplay between topology, electron correlations, and magnetism in a broad range of quantum materials.

Short Bio: Hailong Wang is a research scientist at Center for Memory and Recording Research at University of California, San Diego (UCSD). He received his B.S. in physics from East China Normal University in 2010, and Ph.D. in physics from The Ohio State University in 2015. He worked as a postdoctoral fellow at The Pennsylvania State University and Massachusetts Institute of Technology from 2015 to 2019 before joining UCSD. Hailong’s current research focuses on synthesis of quantum materials and developing quantum sensing techniques for studying emergent condensed matter systems.