Dynamical instability in a Floquet-Driven Dissipative System

TL;DR

This paper investigates how a strong periodic drive causes dynamical instability in an antiferromagnetic Hubbard model, leading to growth of fluctuations and affecting the system's nonequilibrium properties.

Contribution

It reveals the critical drive strength at which magnon damping changes sign, causing instability in a Floquet-driven dissipative system.

Findings

Dynamical instability occurs above a critical drive strength.

Magnon damping sign change leads to growth of fluctuations.

Implications for nonequilibrium distribution and nonlinear dynamics.

Abstract

We analyse the magnon spectrum and distribution function of the antiferromagnetic phase of the Floquet-driven Hubbard model. Above a critical drive strength, we find a dynamical instability, resulting from a change in sign of the magnon damping at a non-zero wavevector. The change in sign means that infinitesimal fluctuations grow with time, corresponding to an instability of the driven state. Implications for the nonequilibrium distribution function and the strong drive nonlinear dynamics are discussed.