Universal chiral quasi-steady states in periodically driven many-body systems

TL;DR

This paper explores how periodically driven many-body systems can exhibit universal chiral quasi-steady states with quantized currents, revealing a new prethermal regime with topological properties in cold atom experiments.

Contribution

It demonstrates the existence of long-lived prethermal states with universal properties in driven many-body systems, linked to topological Floquet band structures.

Findings

Identification of parameter regimes with suppressed inter-band scattering.

Observation of universal, topologically determined steady-state currents.

Potential for experimental realization in cold atom systems.

Abstract

We investigate many-body dynamics in a one-dimensional interacting periodically driven system, based on a partially filled version of Thouless's topologically quantized adiabatic pump. The corresponding single-particle Floquet bands are chiral, with the Floquet spectrum realizing nontrivial cycles around the quasienergy Brillouin zone. For generic filling, with either bosons or fermions, the system is gapless and is expected to rapidly absorb energy from the driving field. We identify parameter regimes where scattering between Floquet bands of opposite chirality is exponentially suppressed, opening a long time window in which the system prethermalizes to an infinite-temperature state restricted to a single Floquet band. In this quasi-steady state, the time-averaged current takes a universal value determined solely by the density of particles and the topological winding number of the populated Floquet band. This remarkable behavior may be readily studied experimentally in recently developed cold atom systems.