Dissipative quasi-particle picture for quadratic Markovian open quantum systems

TL;DR

This paper introduces a dissipative quasi-particle framework to analyze the dynamics of quantum entropies in noninteracting open quantum systems, enabling better understanding of correlation propagation under dissipation.

Contribution

It develops a novel quasi-particle picture for open quantum systems, extending hydrodynamic approaches to mixed states and dissipation.

Findings

Correlations propagate via quasi-particles in dissipative systems

The framework applies to a broad class of noninteracting open systems

Enables efficient computation of quantum entropies in open systems

Abstract

Correlations between different regions of a quantum many-body system can be quantified through measures based on entropies of (reduced) subsystem states. For closed systems, several analytical and numerical tools, e.g., hydrodynamic theories or tensor networks, can accurately capture the time-evolution of subsystem entropies, thus allowing for a profound understanding of the unitary dynamics of quantum correlations. However, so far, these methods either cannot be applied to open quantum systems or do not permit an efficient computation of quantum entropies for mixed states. Here, we make progress in solving this issue by formulating a dissipative quasi-particle picture -- describing the dynamics of quantum entropies in the hydrodynamic limit -- for a general class of noninteracting open quantum systems. Our results show that also in dissipative many-body systems, correlations are generically established through the propagation of quasi-particles.