Fluctuation-Dissipation Theorem in an Isolated System of Quantum Dipolar Bosons after a Quench

TL;DR

This paper investigates the validity of fluctuation-dissipation relations in isolated quantum dipolar bosonic systems after a quench, revealing conditions under which these relations hold or fail based on integrability.

Contribution

It demonstrates how fluctuation-dissipation relations depend on the integrability of the system before and after a quench in quantum dipolar bosons.

Findings

FDR hold in nonintegrable post-quench systems

FDR hold if initial state is from a nonintegrable Hamiltonian

FDR fail in fully integrable quench scenarios

Abstract

We examine the validity of fluctuation-dissipation relations in isolated quantum systems taken out of equilibrium by a sudden quench. We focus on the dynamics of trapped hard-core bosons in one-dimensional lattices with dipolar interactions whose strength is changed during the quench. We find that fluctuation-dissipation relations hold if the system is nonintegrable after the quench. They also hold if the system is integrable after the quench if the initial state is an equilibrium state of a nonintegrable Hamiltonian. However, they fail if the system is integrable both before and after quenching.