Periodically driven (Floquet) systems provide an intriguing landscape for studying novel phases of non-equilibrium matter. In this talk, I will describe recent advances, surrounding the idea of time translation symmetry breaking --- the resulting discrete time crystal exhibits collective subharmonic oscillations. Particular care will be taken to contextualize modern results on discrete time crystals with related phenomena in non-linear dynamical systems. The focus of the talk will be on showing that locally-interacting, Floquet Hamiltonian dynamics coupled to a Langevin bath support finite-temperature discrete time crystals with an infinite auto-correlation time. Our approach utilizes a general mapping from probabilistic cellular automata (PCA) to open classical Floquet systems. Applying this mapping to a variant of the Toom cellular automata leads to a 2D Floquet Hamiltonian with a finite-temperature period-doubling phase transition. Finally, I will discuss how general results from the field of probabilistic cellular automata imply the existence of discrete time crystals in all dimensions, d > 0.
Boxed lunches will be served at 11:15am - 12:00pm outdoors in the Varian courtyard. No food is allowed inside the seminar room. RSVP required.
Meeting ID: 914 8268 2357; Password available after registration.
BIO: Norman Yao joined the physics department as an assistant professor in the summer of 2016. He received his A.B. summa cum laude with highest honors in physics and mathematics from Harvard University in 2009. After completing his Ph.D. at Harvard in 2014, he began postdoctoral work at UC Berkeley as a Miller Fellow. He is the recipient of the Radcliffe Institute's Captain Jonathan Fay Prize (2009), the Deborah Jin Award for Outstanding Doctoral Thesis Research in Atomic, Molecular, or Optical Physics (2015), the NSF CAREER award (2017), the Alfred P. Sloan Fellowship (2018), the David and Lucile Packard Fellowship in Science and Engineering (2018) and the APS George E. Valley Jr. Prize (2020).
Q-FARM Seminars are held biweekly on Wednesdays, from 12-1pm. See website for our upcoming schedule.