Decoherence in a nonequilibrium environment

TL;DR

This paper develops a framework to quantify decoherence in a quantum harmonic oscillator coupled to a nonequilibrium environment, introducing an effective temperature concept and proposing an experimental scheme for its measurement.

Contribution

It introduces a measurable effective temperature to describe nonequilibrium decoherence and provides a unified formalism for non-Markovian noise sources.

Findings

Decoherence factor expressed via effective temperature.

Proposed experimental scheme in a linear Paul trap.

Quantitative description of nonequilibrium decoherence.

Abstract

We consider a quantum harmonic oscillator coupled to a general nonequilibrium environment. We show that the decoherence factor can be expressed in terms of a measurable effective temperature, defined via a generalized fluctuation-dissipation relation. We further propose a simple experimental scheme to determine the time-dependent effective temperature in a linear Paul trap with engineered reservoirs. Our formalism allows quantitative description of nonequilibrium decoherence in the presence of an arbitrary number of non-Markovian noise sources in a unified manner.