Heating Dynamics of Correlated Fermions under Dephasing

TL;DR

This paper investigates how correlated fermions dissipate energy and thermalize under local dephasing, revealing complex spectral behavior and distinct thermalization processes compared to closed systems.

Contribution

It introduces a DMFT-based approach to analyze heating and thermalization in open quantum systems with correlated fermions under dephasing.

Findings

Dissipative dynamics lead to heating towards infinite temperature.

Steady-state spectral functions show interplay between quasiparticles and dephasing.

Thermalization in open systems differs qualitatively from closed systems.

Abstract

We study the dissipative dynamics of correlated fermions evolving in presence of a local dephasing bath. To this extent we consider the infinite coordination limit of the corresponding Lindblad master equation, provided by Dynamical Mean-Field Theory for open quantum systems. We solve the resulting quantum impurity problem, describing an Anderson impurity coupled to a local dephasing, using weak-coupling perturbation theory in interaction and dephasing. We show that the dissipative dynamics describes heating towards infinite temperature, with a relaxation rate that depends strongly on interaction. The resulting steady-state spectral functions are however non-trivial and show an interplay between coherent quasiparticle peak and local dephasing. We then discuss how thermalization towards infinite temperature emerges within DMFT, by solving the impurity problem throughout its self-consistency. We show that thermalization under open quantum system dynamics is qualitatively different from the closed system case. In particular, the thermalization front found in the unitary is strongly modified, a signature of the irreversibility of the open system dynamics.