Physics Department Seminar: Dr. Yuping Huang, Northwestern University; Zeno’s Paradox of “Achilles and the Tortoise”

A Revisit and its Applications in Quantum Optics

Friday, April 4, 2014 ( 1:30 pm to 3:00 pm )

Location: Babbio Center 310

ABSTRACT

The "Achilles and the Tortoise" Paradox, raised by Zeno of Elea more than 2000 years ago, has led to the discovery of quantum Zeno effect (QZE) by which the motion of a system can be frozen through frequent observation of its quantum state. Demonstrated first in a system of two-level atoms in 1989, QZE is still one of the most mysterious and fascinating effects in the quantum wonderland. In this talk, I will first discuss the fundamental physics underlying the QZE and some counter-intuitive phenomena it gives rise to. Then, I will present some unexpected, powerful applications of QZE in the broad field of quantum optics. These include a) deterministic quantum logic with single atoms and single photons; b) decoherence-free phase gates with laser-excited semiconductor quantum dots; c) a class of "interaction-free" logic operations for quantum photonic signals. Lastly, I will report two recent experiments in which we observed QZE effects in an all-optical environment using a nonlinear Fabry-Perot cavity and a whispering-gallery-mode microcavity, respectively. The theoretical and experimental results, as a whole, have identified a promising platform for next-generation all-optical information processing in both quantum and classical domains, whose distinct advantages include ultrahigh energy efficiency, absence of critical biasing, and fan-in/out capability.

BIOGRAPHY

Dr. Yu-Ping Huang received the B.Sc. degree in physics from the University of Science and Technology of China, Hefei, China, in 2004, and the Ph.D. degree in physics from Michigan State University, East Lansing, MI, in 2009. After graduation, he joined the Center for Photonic Communication and Computing, Northwestern University, Evanston, IL, where he has been a research assistant professor and a principal investigator since 2012. His research covers experimental and theoretical areas of nonlinear and quantum optics in optical fibers, waveguides, and microresonators, quantum computing, quantum telecommunications, atom optics, and quantum-degenerate gases.