Quantum discord as a tool for comparing collapse models and decoherence

TL;DR

This paper proposes using quantum discord to compare collapse models and decoherence mechanisms, aiming to detect and bound collapse parameters through macroscopic entanglement experiments.

Contribution

It introduces quantum discord as a novel tool for contrasting collapse models and decoherence, and for experimentally detecting and bounding collapse parameters.

Findings

Quantum discord can distinguish collapse effects from decoherence.

Experimental timescales for detecting collapse or decoherence are identified.

Bounds on collapse parameters are derived from quantum discord measurements.

Abstract

The quantum to classical transition maybe caused by decoherence or by dynamical collapse of the wave-function. We propose quantum discord as a tool, 1) for comparing and contrasting the role of a collapse model (Continuous Spontaneous Localization) and various sources of decoherence (environmental and fundamental), 2) for detecting collapse model and fundamental decoherence for an experimentally demonstrated macroscopic entanglement. We discuss the experimental times which will lead to the detection of either Continuous Spontaneous Localization or fundamental decoherence. We further put bounds on the collapse parameters from this experiment for quantum discord.