Seminars And Colloquia Next Week

ics Atomic
Monday, September 25, 2017
3:30 PM
Physics Building, Room 204
Zubin Jacob [Host: Olivier Pfister]
Purdue University
"Fock state responsivity of single photon detectors"

Highly efficient single photon detectors are ubiquitous in quantum optics and atomic physics. However, many of the theories of single photon detection still arise from the Glauber theory of photodetection which was primarily developed for inefficient detectors (weak light-matter coupling). The first goal of the talk is to contrast the photon counting mechanism in photomultiplier tubes (PMTs), single photon avalanche diodes (SPADs), single electron transistor based photodetectors (SET-PDs) and superconducting nanowire single photon detectors (SNSPDs). This can help develop a general model for single photon detection beyond Glauber's theory. 

Secondly, we will present experimental results on time-correlated single photon counting experiments that demonstrate long range dipole-dipole interactions between quantum emitters mediated by metamaterials.   We will discuss a fundamental limit to the efficiency of energy transfer between quantum emitters and discuss routes to achieve this limit through induced coherence. Our approach to engineering dipole-dipole interactions can motivate experiments from atomic systems (eg: Rydberg blockade) to biochemistry (Forster/Dexter resonance energy transfer).

ics Nuclear
Tuesday, September 26, 2017
3:30 PM
Physics Building, Room 204

ics Condensed Matter
Thursday, September 28, 2017
11:00 AM
Physics Building, Room 313
Dmytro Pesin [Host: Gia-Wei Chern]
University of Utah
"Geometric theory of nonlocal transport in metals"

I will discuss the topological and geometric aspects of optical
and transport phenomena in metals with nontrivial band geometry, and outline
the full theory of linear-in-q contribution to the non-local conductivity in
a disordered metal. Physical applications of the theory include the natural
optical activity of metals and the dynamic chiral magnetic effect, as well
as the kinetic magnetoelectric effect/the current-induced magnetization in
metallic systems. The theory is similar in spirit to the one of the
anomalous Hall effect in metals, and can be used for the analysis of the
typical optical and transport measurements (e.g. Faraday rotation,
current-induced magnetization) in the THz frequency range.


ics Colloquium
Friday, September 29, 2017
3:30 PM
Physics Building, Room 204
Xiaochao Zheng [Host: Joe Poon]
"Peeling the Atomic Onion"

The word "atom" (a-tomos) originates from ancient Greek philosophers, who argued that objects can be eventually divided into discrete, small particles, beyond which matter is no longer cuttable.  Our search for the answer to "What the matter is made of" has gone a long way, from the first experimental evidence of atoms in the 1800's, to Rutherford's alpha scattering on gold foils, to modern day's linear accelerators looking into the atomic nucleus. We now understand that matter is made of quarks and leptons, currently named elementary particles (objects of no size) that form the foundation of the Standard Model of Particle Physics. However, if we look back at this journey, one may wish to oppose the view of the ancient Greeks and argue that quarks and leptons cannot be the end of the story, that our quest for peeling the atomic onion may be a timeless journey.

I will discuss the frontier research in electron scattering at the GeV energy level. I will focus on parity violation in electron scattering off the proton and the neutron and the extraction of neutral-weak effective couplings between electrons and quarks, and show how such high precision measurements are now helping us venturing further into the study of subatomic structure. 

To add a speaker, send an email to phys-speakers@Virginia.EDU. Please include the seminar type (e.g. Seminars and Colloquia), date, name of the speaker, title of talk, and an abstract (if available).