Interaction-Induced Quantum Dephasing in Mesoscopic Rings

TL;DR

This paper shows that quantum coherence in a particle on a ring is suppressed beyond a certain length due to interactions with a diffusive electron gas, even at zero temperature, using nonperturbative and Monte Carlo methods.

Contribution

It introduces a nonperturbative approach combined with Monte Carlo simulations to analyze quantum dephasing caused by interactions in mesoscopic rings.

Findings

Quantum coherence is suppressed beyond a finite length $L_{\phi}$ at zero temperature.

The length $L_{\phi}$ matches values derived from weak localization analysis.

Long-range Coulomb interactions induce quantum dephasing in mesoscopic systems.

Abstract

Combining nonperturbative techniques with Monte Carlo simulations we demonstrate that quantum coherence effects for a particle on a ring are suppressed beyond a finite length $L_{\phi}$ even at zero temperature if the particle is coupled to a diffusive electron gas by means of long range Coulomb interaction. This length is consistent with $L_{\phi}$ derived from weak-localization-type of analysis.