Description:

Speaker: Professor Mark Dykman, Michigan State University

Title: Floquet dynamics of nonlinear oscillators and time-translation symmetry breaking

Abstract: A periodically driven system has discrete time-translation symmetry with the period of the driving. Its quantum dynamics is described in terms of the Floquet states. Generally, if the system is in a Floquet state, its dynamical variables oscillate with the period of the driving. Recently much interest have attracted systems where the time symmetry is broken, the “time crystal” effect. Nonlinear oscillators provide an ideal platform for studying this effect. A familiar example is parametric resonance: when a dissipative oscillator is modulated close to twice the eigenfrequency, the period of the parametrically excited vibrations is twice the modulation period. We will show that the symmetry breaking may occur also in the quantum coherent regime and discuss the transition to the incoherent regime. The results fill in the gap between the topologically protected broken-symmetry states in extended systems and multiple-period states in dissipative systems.

Hosts: Jim Sauls, Jens Koch