Non-equilibrium quantum phase transition via entanglement decoherence dynamics

TL;DR

This paper studies how entanglement decoherence in a quantum system undergoes a nonequilibrium phase transition as the coupling strength with the environment increases, revealing a phase diagram for different spectral densities.

Contribution

It analytically characterizes the nonequilibrium quantum phase transition in entanglement decoherence across all Ohmic spectral densities.

Findings

Localized modes prevent the system from reaching equilibrium in strong coupling.

The phase transition occurs at varying coupling strengths depending on spectral density.

A 3-D entanglement quantum phase diagram is constructed.

Abstract

We investigate the decoherence dynamics of continuous variable entanglement as the system-environment coupling strength varies from the weak-coupling to the strong-coupling regimes. Due to the existence of localized modes in the strong-coupling regime, the system cannot approach equilibrium with its environment, which induces a nonequilibrium quantum phase transition. We analytically solve the entanglement decoherence dynamics for an arbitrary spectral density. The nonequilibrium quantum phase transition is demonstrated as the system-environment coupling strength varies for all the Ohmic-type spectral densities. The 3-D entanglement quantum phase diagram is obtained.