Time scale of stationary decoherence

TL;DR

This paper investigates the timescale of stationary decoherence for a particle in an ideal gas, revealing that quantum coherence in the environment can slow down decoherence compared to diffusion, with the decoherence time being comparable to or longer than the diffusion time.

Contribution

It derives the effective Lagrangian for the system and analyzes the stationary decoherence time, highlighting the influence of environmental quantum coherence on decoherence dynamics.

Findings

Decoherence time is comparable to or longer than diffusion time.

Decoherence is minimized in a classical, fully decohered environment.

Quantum coherence in the environment slows down the decoherence process.

Abstract

The decoherence of a test particle interacting with an ideal gas is studied by the help of the effective Lagrangian, derived in the leading order of the perturbation expansion and in order $\ord{\partial^2_t}$. The stationary decoherence time is found to be comparable to or longer than the diffusion time. The decoherence time reaches its minimal value for classical, completely decohered environment, suggesting that physical decoherence is slowed down as compared with diffusion by the quantum coherence of the environment.