Asymptotic Floquet states of a periodically driven spin-boson system in the nonperturbative coupling regime

TL;DR

This paper investigates the long-term behavior of a driven spin-boson system beyond weak coupling, revealing complex asymptotic states through a novel Floquet analysis of non-Markovian dynamics.

Contribution

It introduces a method to evaluate Floquet dynamics in non-Markovian open quantum systems, enabling the study of asymptotic states under strong coupling and periodic driving.

Findings

Identification of nontrivial asymptotic states in the nonperturbative regime

Development of a Floquet analysis method for non-Markovian systems

Insights into the interplay between dissipation and external modulation

Abstract

As a paradigmatic model of open quantum system, the spin-boson model is widely used in theoretical and experimental investigations. Beyond the weak coupling limit, the spin dynamics can be described by a time-nonlocal generalized master equation with a memory kernel accounting for the dissipative effects induced by the bosonic environment. When the spin is additionally modulated by an external time-periodic electromagnetic field, the interplay between dissipation and modulations yields a spectrum of nontrivial asymptotic states, especially in the regime of nonlinear response. Here we implement a method for the evaluation of Floquet dynamics in non-Markovian systems [L. Magazz\`u et al., Phys. Rev. A 96, 042103 (2017)] to find these strongly non-equilibrium states.