Past Events

Abstract: Spin glasses—large-scale networks of spins with deeply frustrated interactions—are canonical examples of complex matter. Although much about their structure remains uncertain, they inform the description of a wide array of complex phenomena, ranging from magnetic ordering in metals with impurities to aspects of evolution, protein folding, climate models, and combinatorial optimization. Indeed, spin glass theory forms a mathematical basis for neuromorphic computing and brain modeling.

Abstract: Many-body quantum games provide a natural perspective on phases of matter in quantum hardware, crisply rel

Abstract: 

Abstract: I will review some modern applications of effective field theories outside their traditional particle physics domain. In particular, I will focus on spontaneous symmetry breaking for spacetime symmetries. The effective theories for the associated Goldstone excitations capture the low-energy/long-distance dynamics of a number of physical systems, from ordinary macroscopic media (solids, fluids, superfluids, supersolids) to more exotic cosmological ones.

The past decade has seen a huge wave of interest in the possibility of hydrodynamic transport of electrons and/or phonons in quantum materials.  There are now dozens of experiments that are approaching consensus on a weakly viscous hydrodynamic regime in e.g. monolayer graphene.

Abstract: Neutral atom quantum computing is a rapidly developing field. Exploring new atomic species, such as alkaline earth atoms, provides additional opportunities for cooling and trapping, measurement, qubit manipulation, high-fidelity gates and quantum error correction. In this talk, I will present recent results from our group on implementing high-fidelity gates on nuclear spins encoded in metastable 171Yb atoms [1], including mid-circuit detection of gate errors that give rise to leakage out of the qubit space, using erasure conversion [2,3].

Please join us for a special edition of our PEAR Boulder monthly seminar series on Tuesday, April 30th at 11 am MT (1 pm ET) in conference room 1-1107 or online at https://nist.zoomgov.com/j/1601226156?pwd=aWpSMklZRWNxWGxLWXFmVVdRMEQrU….

We have two speakers from JILA (Joint Institute for Laboratory Astrophysics), Jacob S. Higgins and Kyungtae Kim, both from Prof. Jun Ye’s research group. JILA is a joint institute between NIST and the University of Colorado Boulder.

Abstract: Black hole X-ray binaries and Active Galactic Nuclei transition through a series of accretion states in a well-defined order. During a state transition, the accretion flow changes from a hot geometrically thick accretion flow, emitting a power-law–like hard spectrum to a geometrically thin, cool accretion flow, producing black-body–like soft spectrum.

Abstract: The rare earth elements, hidden at the bottom of the periodic table and long neglected, have risen to prominence at the end of the 20th century. Their unique electronic configuration form the basis for a variety of lasers, photonic applications, strong and exotic magnetism, defining many modern technologies. I will tell a story connecting from the basic science of the geology of Colorado and rare earth and other rare element mineralogy, to our technological and societal dependence and questions of strategic element security. 

Abstract: The climate crisis is driving a new era of electrification around the globe.  The decarbonization of transportation and industrial processes is expected to make a significant impact on the rate of climate change.  For example, the electrification of refineries and the broader chemical industry has the potential to lead to major reductions in fossil fuel consumption and lower the production of harmful greenhouse gases contributing to climate change.  New components including electrode materials and electrolytes are being discovered quickly and are necessary to engi

Abstract

Abstract: The discovery of Earth’s Van Allen radiation belts in 1958 revealed the hazardous radiative environment for spacecraft operating within. Understanding, modeling, and eventually predicting the dynamics of energetic electrons in the radiation belts have long been targets that space physicists have pursued. Since the launch of NASA Van Allen Probes in 2012, significant progress has been achieved in understanding the strong enhancement of relativistic electrons in the radiation belt.

Abstract: The emergence of quasiparticles with fractional charge and fractional statistics is an essential feature of fractional quantum Hall states, which occur in two-dimensional electron gas under a strong magnetic field. An interesting question is whether fractional electron states can form spontaneously in quantum materials without the external magnetic field.

Abstract: Ancient remnants from the early universe surround our galaxy, which you may know as globular clusters. Although now on their old age, understanding how these clusters were formed has the potential to provide insight into the physical conditions that prevailed during an epoch that cannot be directly observed. We now know that globular clusters can form during extreme episodes of star formation in the relatively nearby universe, but the actual physical conditions that give rise to globular clusters have vexed both observers and theorists for decades.

Abstract: Reliable theoretical prediction of complex chemical processes in condensed phases requires an accurate quantum mechanical description of interatomic interactions.  If these are to be used in a molecular dynamics calculation, they are often generated “on the fly” from approximate solutions of the electronic Schrödinger equation as the simulation proceeds, a technique known as ab initio molecular dynamics (AIMD).   However, due to the high computational cost of these quantum calculations, alternative approaches employing machine learning methods represent an attract

Abstract:  The average quantum physicist on the street would say that a quantum-mechanical