Study of critical behavior of periodically driven cold atomic system

Myoung-Sun Heo, Yong Hee Kim, Wonho Jhe +1 more

Myoung-Sun Heo, Ki-hwan Lee, Changil Ryoo +4 more

Tista Banerjee, Suchetan Das, K. Sengupta

We study the dynamics of entanglement asymmetry in periodically driven quantum systems. Using a periodically driven XY chain as a model for a driven integrable quantum system, we provide semi-analytic results for the behavior of the dynamics of the entanglement asymmetry, \Delta S Δ S , as a function of the drive frequency. Our analysis identifies special drive frequencies at which the driven XY chain exhibits dynamic symmetry restoration and displays quantum Mpemba effect over a long timescale; we identify an emergent approximate symmetry in its Floquet Hamiltonian which plays a crucial role for realization of both these phenomena. We follow these results by numerical computation of \Delta S Δ S for the non-integrable driven Rydberg atom chain and obtain similar emergent-symmetry-induced symmetry restoration and quantum Mpemba effect in the prethermal regime for such a system. Finally, we provide an exact analytic computation of the entanglement asymmetry for a periodically driven conformal field theory (CFT) on a strip. Such a driven CFT, depending on the drive amplitude and frequency, exhibits two distinct phases, heating and non-heating, that are separated by a critical line. Our results show that for m m cycles of a periodic drive with time period T T , \Delta S \sim \ln mT Δ S ∼ ln m T [ \ln (\ln mT) ln ( ln m T ) ] in the heating phase [on the critical line] for a generic CFT; in contrast, in the non-heating phase, \Delta S Δ S displays small amplitude oscillations around it’s initial value as a function of mT m T . We provide a phase diagram for the behavior of \Delta S Δ S for such driven CFTs as a function of the drive frequency and amplitude.

Myoung-Sun Heo, Wonho Jhe

We realize an ideal mean-field transition of time-translation symmetry in a periodically-driven atomic system. The symmetry in steady-state oscillatory atomic motions spontaneously changes with the total number of atoms due to the interplay between inter-atomic interactions which originate from the attenuation effects in the trapping laser light and thermal fluctuations. A large separation of the time scales governing the transition suppresses the spatial dependence of the system dynamics, leading to a mean-field behavior even close to the transition point.

Christopher J. Foot

Dmitry A. Abanin, Wojciech De Roeck, François Huveneers

We derive general bounds on the linear response energy absorption rates of periodically driven many-body systems of spins or fermions on a lattice. We show that, for systems with local interactions, the energy absorption rate decays exponentially as a function of driving frequency in any number of spatial dimensions. These results imply that topological many-body states in periodically driven systems, although generally metastable, can have very long lifetimes. We discuss applications to other problems, including the decay of highly energetic excitations in cold atomic and solid-state systems.