Environment-Mediated Long-Ranged Correlations in Many-Body System

TL;DR

This paper investigates how environmental effects induce long-range temporal correlations in many-body quantum systems, using advanced simulation methods to explore complex dynamical phases in spin chains.

Contribution

It introduces the QD-MESS approach to simulate reservoir-induced correlations in large quantum systems with non-Markovian environments.

Findings

Identification of dissipative phase transitions

Observation of rich spatiotemporal correlation patterns

Analysis of thermal and quantum fluctuation interplay

Abstract

Quantum states in complex aggregates are unavoidably affected by environmental effects, which typically cannot be accurately modeled by simple Markovian processes. As system sizes scale up, nonperturbative simulation become thus unavoidable but they are extremely challenging due to the intimate interplay of intrinsic many-body interaction and time-retarded feedback from environmental degrees of freedom. In this work, we utilize the recently developed Quantum Dissipation with Minimally Extended State Space (QD-MESS) approach to address reservoir induced long-ranged temporal correlations in finite size Ising-type spin chains. For thermal reservoirs with ohmic and subohmic spectral density we simulate the quantum time evolution from finite to zero temperature. The competition between thermal fluctuations, quantum fluctuations, and anti-/ferromagnetic interactions reveal a rich pattern of dynamical phases including dissipative induced phase transitions and spatiotemporal correlations.