Spatial Correlation in Matter Wave Interference as a Measure of Decoherence, Dephasing and Entropy

TL;DR

This paper introduces a method using spatial correlation functions in matter wave interference patterns to differentiate between dephasing and decoherence, aiding in understanding quantum-to-classical transition and experimental contrast loss.

Contribution

It presents a novel approach to measure decoherence and dephasing effects without requiring coherence term analysis of the density matrix.

Findings

Spatial correlation functions distinguish dephasing from decoherence.

The method provides a measure of time-reversibility independent of coherence terms.

Applicable to studying quantum-classical transition and experimental contrast loss.

Abstract

The loss of contrast in double-slit electron-diffraction due to dephasing and decoherence processes is studied. It is shown that the spatial correlation function of diffraction patterns can be used to distinguish between dephasing and decoherence. This establishes a measure of time-reversibility that does not require the determination of coherence terms of the density matrix, while von Neumann entropy, another measure of time-reversibility, does require coherence terms. This technique is exciting in view of the need to understand and control the detrimental experimental effects of contrast loss and for fundamental studies on the transition from the classical to the quantum regime.