Quantum Information Science (QIS) Seminar

(CSI 991 - 006)

Monday, September 26, 2005, 4:30 - 6:00 PM

George Mason University, Fairfax Campus
Science Showcase, George Johnson Center, Room 237

Presenter: Lang Withers, Jr.  George Mason University

Title: Inequalities Relating Measures of Divergence between Mixed Quantum          States

Abstract: An inequality that relates two important measures of the difference of two states, the fidelity angle and the relative entropy, is proved.  The fidelity measure is related to a simpler form of fidelity.  It is shown that this fidelity and the relative entropy reduce to their classical forms for suitably defined joint probability densities.  Finally, a related quantum-theoretic version of the classical AM-GM family of divergences is introduced.

About the Speaker: Mr. Lang Withers, Jr. has an MA in mathematics from the University of Colorado at Boulder and has worked in northern Virginia for 30 years on signal processing algorithms and related areas.  He joined the MITRE Signal Processing Center in July 2004, where he works on multi-antenna (MIMO) wireless communications.  Earlier, he worked for Raytheon/Falls Church and at NRL.  Having three daughters who have grown up, he has enrolled in the SCS Computational Sciences Ph.D. program at GMU.  In this program, he is concentrating on quantum physics theory and applications.