Correlations in atomic systems: Diagnosing coherent superpositions

TL;DR

This paper presents a method to extract higher order quantum correlations from single measurements in atomic systems, enabling detection of subtle phase coherence in mesoscopic superpositions.

Contribution

It introduces a measurement-based approach to diagnose quantum correlations and phase coherence using simple models akin to quantum optics techniques.

Findings

Higher order correlation functions can be extracted from individual measurements.

The method detects subtle phase coherence in mesoscopic superpositions.

Single measurements contain sufficient information about quantum correlations.

Abstract

While investigating quantum correlations in atomic systems, we note that single measurements contain information about these correlations. Using a simple model of measurement -- analogous to the one used in quantum optics -- we show how to extract higher order correlation functions from individual "phtotographs" of the atomic sample. As a possible application we apply the method to detect a subtle phase coherence in mesoscopic superpostitions.