John Nichol
Associate Professor, Department of Physics and Astronomy, University of Rochester

Dark States in Silicon

Electron spins in semiconductor quantum dots typically interact with many nuclear spins in their semiconductor environments, realizing a manifestation of the central spin problem. The central spin problem is a widely studied model of decoherence and is predicted to exhibit a rich variety of interesting and useful phenomena, only some of which have been observed. In this talk, I will discuss a series of experiments exploring these dynamics in silicon quantum dots. We report evidence for the formation of a nuclear dark state, which occurs when the nuclei are driven into a state that does not interact with the electrons. We show evidence that this dark state depends on the synchronized precession of the nuclear spins, and that driving the nuclear spins into the dark state promotes increased lifetimes of electronic spin states. We also discuss the relationship between the dark state and the coherence time of electronic spin states.

Hosted by Valla Fatemi

Pizza served starting at 12:10 p.m.
Please bring your own beverage

About the speaker: Professor Nichol received a B.A. from St. Olaf College in 2006 and a Ph.D. in physics from University of Illinois at Urbana-Champaign in 2013. After working as a postdoctoral associate at Harvard University, he joined the University of Rochester in 2016 as an assistant professor in the Department of Physics and Astronomy. He is the recipient of a National Science Foundation CAREER award, a Google Research Scholar Award, and the Leonard Mandel Faculty Fellow Award.