Physics Home

PHYSICS COLLOQUIUM SCHEDULE
Fall 2020

The Colloquia are via Zoom on Thursdays at 4:05 PM

Contact: D. Tanner uftanner@ufl.edu)
Department of Physics Colloquium Committee:
Tanner (chair), Fulda, Matchev, Mitselmakher, Wang


August 27

  Speaker
  Title
  Abstract
  Host

September 3

  Speaker Graduate Student Meeting with Dr. Xiaoguang Zhang 4:00pm in 1002 NPB
  Title
  Abstract
  Host

September 8 - Special Colloquium

  Speaker Sergei Klimenko
  Title GW190521: an “Impossible” Binary Black Hole
  Abstract With the first direct observation of gravitational waves (GW) on September 14, 2015, the advanced LIGO detectors opened new possibilities to explore our Universe. This first GW signal was not from the much-anticipated binary neutron star inspiral (BNS), but from a quite unexpected merger of binary black holes (BBH). Now, five years later, the LIGO GW detectors have recorded two BNS and more than 50 BBH signals, including GW190521?a possible missing link between stellar-mass black holes and supermassive black holes. This is another unexpected BBH event, which informs our understanding of the evolution of the most massive stars and the growth of massive black holes. I will talk about the LIGO detectors, data analysis, and detections of the most cataclysmic astrophysical events in the Universe.
  Host

September 10 - No Colloquium

  Speaker
  Title
  Abstract
  Host

September 17

  Speaker Giovanni Vignale, University of Missouri - https://ufl.zoom.us/j/91807944357
  Title Hydrodynamics of quantum electron liquids
  Abstract Electric and thermal transport in electronic systems has long been described in terms of a single-particle picture, which emphasizes the role of collisions between electrons and impurities or phonons, while electron-electron collisions play a secondary role. It is only in the past two decades that advances in the fabrication of ultra clean samples have refocused the interest on collective hydrodynamic transport - a transport regime which is controlled by the nearly conserved quantities: number, momentum, and energy, and by electron-electron interactions. In this talk I review some of the recent theoretical and experimental progress in our understanding of electronic hydrodynamics in graphene-based materials. I focus on thermal transport and its relation to electric transport, epitomized by the Wiedemann-Franz law which, in its conventional form, predicts a universal ratio between electric and thermal resistivities. Significant deviations from this prediction are found in single layer and double layer graphene, both in the doped case, where the Wiedemann-Franz ratio is reduced, and in the undoped case, where it is greatly enhanced. In the latter case an interesting scenario emerges, in which a small amount of disorder helps to expose an underlying singularity of the transport coefficients: vanishing thermal resistivity, finite electric resistivity, and diverging Wiedemann-Franz ratio and Seebeck coefficient.
  Host

September 24

  Speaker
  Title
  Abstract
  Host

October 1

  Speaker
  Title
  Abstract
  Host

October 8

  Speaker Joachim Kopp, CERN
  Title A Fourth Neutrino?
  Abstract Neutrinos have come a long way from being considered undetectable to being the focus point of billion-dollar experiments. And while we have learned a lot about their properties over the past decades, the standard theory of neutrinos has a few noteworthy dents in the form of seemingly anomalous experimental results. We review these anomalies and use them to illustrate some of the challenges in making reliable theoretical predictions for neutrino experiments. We also speculate about the possibility that the anomalies are indeed harbingers of "new physics" in the form of a yet-unknown extra neutrino species.
  Host Wei Xue

October 15

  Speaker Giovanni Villadoro, ICTP
  Title Axion Dark Matter
  Abstract The axion is an hypothetical particle introduced more than 40 years ago to explain the absence of large time-reversal symmetry violations in strong nuclear interactions. If it exists it could easily explain one of the present mysteries of our Universe, the nature of dark matter. While the axion dynamics is governed by extremely simple equations it gives rise to a plethora of fascinating and complex effects, some of which have important consequences both for experimental searches and for the evolution of the Universe. After introducing the basic notions of axion physics and the status of experimental searches I will discuss recent developments in the understanding of the dynamics and evolution of axion dark matter.
  Host Wei Xue

October 22

  Speaker
  Title
  Abstract
  Host

October 29

  Speaker
  Title
  Abstract
  Host

November 5

  Speaker Geoff Potvin, Florida International University
  Title APS-IDEA: Empowering physics organizations to improve equity, diversity and inclusion
  Abstract Among STEM disciplines, physics has particularly lagged in including diverse participants across the educational spectrum. The APS-IDEA project, funded in 2019 by the American Physical Society's Innovation Fund, seeks to empower and support physics departments, laboratories, and collaborations to identify and enact strategies for improving equity, diversity and inclusion (EDI) through the creation of a national network of similarly-motivated organizations. The network now includes nearly 100 organizations from the U.S. and around the world which are undertaking the long and difficult tasks necessary for improving EDI. In this talk, I will present some of the research that led me to co-founding the APS-IDEA project (including the STEP UP project - stepupphysics.org), the mission and scope of APS-IDEA, its emerging community of transformation, and future plans for the network. More details about APS-IDEA can be found at Among STEM disciplines, physics has particularly lagged in including diverse participants across the educational spectrum. The APS-IDEA project, funded in 2019 by the American Physical Society's Innovation Fund, seeks to empower and support physics departments, laboratories, and collaborations to identify and enact strategies for improving equity, diversity and inclusion (EDI) through the creation of a national network of similarly-motivated organizations. The network now includes nearly 100 organizations from the U.S. and around the world which are undertaking the long and difficult tasks necessary for improving EDI. In this talk, I will present some of the research that led me to co-founding the APS-IDEA project (including the STEP UP project - stepupphysics.org), the mission and scope of APS-IDEA, its emerging community of transformation, and future plans for the network. More details about APS-IDEA can be found at https://www.aps.org/programs/innovation/fund/idea.cfm.
  Host Mark Meisel

November 12

  Speaker Stefan Ballmer, Syracuse
  Title Building the Next Terrestrial Gravitational Wave Detectors
  Abstract The newly released O3a Gravitational-Wave Transient Catalog from the Advanced LIGO and Advanced Virgo for the first time provides a non-trivial sample of actual gravitational-wave sources. Thus for the first time we can design the next-generation detectors with good guidance on the observable signals. This talk will discuss the latest results, and then focus on the detector technology currently used in Advanced LIGO, its sensitivity limitations and the plans for the next-generation detectors Cosmic Explorer and Einstein Telescope. In partiucular, it will highlight the technology developments needed for those detectors.
  Host Paul Fulda

November 19

  Speaker Aashish Clerk, University of Chicago
  Title One-way quantum interactions for fun and profit
  Abstract The most common kinds of interactions in physics obey a basic kind of reciprocity: when two systems or particles interact, each one influences the other, and information flows in both directions. In this talk, I’ll discuss general methods for engineering interactions that break this symmetry, in a fully consistent quantum setting. These engineered “one-way” quantum interactions open up a host of unusual possibilities, from new methods for manipulating and processing quantum information, to new kinds of topological and many-body physics. I’ll introduce some of the basic theoretical ideas that underlie these unusual interactions, and connections to recent interest in “non-Hermitian” quantum systems. I’ll also discuss recent experimental implementations in quantum optomechanical systems and superconducting quantum circuits.
  Host Selman Hershfield

December 3

  Speaker Aaron Spector, Deutsches Elektronen-Synchrotron (DESY)
  Title Shining Light into the Hidden Sector with ALPS II
  Abstract The strong CP problem, the existence of dark matter, the transparency of interstellar space to highly energetic photons, anomalies in stellar cooling rates, all of these phenomena suggest that our current understanding of the universe is incomplete. Axions and axion-like particles residing somewhere in the hidden sector could provide a singular solution to this puzzle. The Any Light Particle Search II (ALPS II) is an experiment based at DESY in Hamburg, Germany, that will hunt for low mass (< 0.1 meV) axion-like particles by taking advantage of their coupling to photons in the presence of a magnetic field. ALPS II will use the light-shining-through-a-wall (LSW) technique, in which a high-power laser is directed through a magnetic field to generate a beam of relativistic axion-like particles that then pass through a wall. Beyond the wall will be another region of magnetic field, where some of the particles will reconvert back to photons. By counting the individual photons after the wall, ALPS II will perform a model-independent measurement of the coupling strength between photons and axion-like particles. In this talk, I will provide a brief introduction to axions and explain where LSW experiments fit into the broader search for these types particles. An overview and status report of ALPS II will also be given, along with a discussion of the optical system, which includes two 122 m long resonators, and the techniques used to detect single photons.
  Host Guido Mueller



PHYSICS COLLOQUIUM SCHEDULE

Spring 2021

The Colloquia are via Zoom on Thursdays at 4:05 PM

Contact: D. Tanner uftanner@ufl.edu)
Department of Physics Colloquium Committee:
Tanner (chair), Fulda, Matchev, Mitselmakher, Wang


January 14

  Speaker
  Title
  Abstract
  Host

January 21

  Speaker John Klauder, University of Florida
  Title From Harmonic Oscillators to Quantum Gravity
  Abstract Canonical quantization (CQ) has been successful in solving many problems, and is a tool used for nearly all cases. But CQ has not worked well for some problems that have resisted any acceptable solution. Happily, the harmonic oscillator, with -∞ < p,q < ∞, is well solved. However, for the half-harmonic oscillator, where -∞ < p < ∞ while 0 < q < ∞ CQ fails significantly. Likewise, quantum gravity has failed with CQ as well. A new quantization process called affine quantization (AQ) will be introduced. AQ leads to acceptable solutions for the half-harmonic oscillator and shows considerable success for quantum gravity. This lecture will demonstrate the solution of the half-harmonic oscillator and leads to a meaningful Schrödinger equation for quantum gravity, which is in position to seek appropriate solutions from complex differential equations.
  Host Sergei Shabanov

January 28

  Speaker
  Title
  Abstract
  Host

February 4

  Speaker
  Title
  Abstract
  Host

February 11

  Speaker
  Title
  Abstract
  Host

February 18

  Speaker
  Title
  Abstract
  Host

February 25

  Speaker
  Title
  Abstract
  Host

March 4

  Speaker
  Title
  Abstract
  Host

March 11

  Speaker
  Title
  Abstract
  Host

March 18

  Speaker
  Title
  Abstract
  Host

March 25

  Speaker
  Title
  Abstract
  Host

April 1

  Speaker
  Title
  Abstract
  Host

April 8

  Speaker
  Title
  Abstract
  Host

April 15

  Speaker
  Title
  Abstract
  Host