Effect of initial correlations on short-time decoherence

TL;DR

This paper investigates how initial correlations between a particle and its environment influence the early stages of quantum decoherence, revealing that such correlations cause system-dependent effects even at very short times.

Contribution

It provides an analytical evaluation of the short-time decoherence process considering initial thermal correlations, highlighting their impact on system dependence.

Findings

Decoherence is system-independent without initial correlations.

Initial thermal correlations induce system-dependent decoherence.

Temperature influences the degree of system dependence in decoherence.

Abstract

We study the effect of initial correlations on the short-time decoherence of a particle linearly coupled to a bath of harmonic oscillators. We analytically evaluate the attenuation coefficient of a Schroedinger cat state both for a free and a harmonically bound particle, with and without initial thermal correlations between the particle and the bath. While short-time decoherence appears to be independent of the system in the absence of initial correlations, we find on the contrary that, for initial thermal correlations, decoherence becomes system dependent even for times much shorter than the characteristic time of the system. The temperature behavior of this system dependence is discussed.