Assessments of macroscopicity for quantum optical states

TL;DR

This paper proposes three criteria—quantum fluctuation photons, state purity, and distinguishability of branches—to evaluate the macroscopicity of quantum optical states, aiding in quantifying large quantum superpositions.

Contribution

It introduces a set of three criteria for assessing the macroscopicity of quantum optical states, providing a framework for quantification.

Findings

Proposes criteria based on photon fluctuations, purity, and distinguishability.

Provides a systematic approach to quantify macroscopic quantum states.

Facilitates comparison of different large quantum superpositions.

Abstract

With the slow but constant progress in the coherent control of quantum systems, it is now possible to create large quantum superpositions. There has therefore been an increased interest in quantifying any claims of macroscopicity. We attempt here to motivate three criteria which we believe should enter in the assessment of macroscopic quantumness: The number of quantum fluctuation photons, the purity of the states, and the ease with which the branches making up the state can be distinguished.