Dephasing of a particle in a dissipative environment

TL;DR

This paper investigates how a particle's quantum coherence is affected by a dissipative environment with short-range correlations, comparing it to the long-range correlation case, and clarifies the dephasing process with a rigorous definition.

Contribution

It provides a detailed analysis of dephasing in a particle-ring system with short-range environmental correlations, contrasting it with the Caldeira-Leggett model and clarifying the dephasing measure.

Findings

Dephasing behavior differs significantly between short and long correlation environments.

A rigorous dephasing factor independent of semiclassical assumptions is proposed.

Recent Monte-Carlo results on temperature effects are explained within this framework.

Abstract

The motion of a particle in a ring of length L is influenced by a dirty metal environment whose fluctuations are characterized by a short correlation distance $\ell << L$. We analyze the induced decoherence process, and compare the results with those obtained in the opposing Caldeira-Leggett limit ($\ell >> L$). A proper definition of the dephasing factor that does not depend on a vague semiclassical picture is employed. Some recent Monte-Carlo results about the effect of finite temperatures on "mass renormalization" in this system are illuminated.