Demonstrating mesoscopic superpositions in double-well Bose-Einstein condensates

TL;DR

This paper explores the creation of mesoscopic superpositions in double-well Bose-Einstein condensates using Feshbach resonances, and discusses the challenges in experimentally distinguishing these superpositions from statistical mixtures.

Contribution

It demonstrates a method to generate mesoscopic superpositions in double-well BECs and analyzes the experimental difficulties in confirming their quantum coherence.

Findings

Superpositions can be generated in short times using Feshbach resonances.

Distinguishing superpositions from mixtures with standard methods is experimentally challenging.

Creating and detecting coherent superpositions in BECs remains a complex task.

Abstract

The availability of Bose-Einstein condensates as mesoscopic or macroscopic quantum objects has aroused new interest in the possiblity of making and detecting coherent superpositions involving many atoms. In this article we show that it may be possible to generate such a superposition state in a reasonably short time using Feshbach resonances to tune the inter-atomic interactions in a double-well condensate. We also consider the important problem of distinguishing whether a coherent superposition or a statistical mixture is generated by a given experimental procedure. We find that unambiguously distinguishing even a perfect `NOON' state from a statistical mixture using standard detection methods will present experimental difficulties.