Observation of transverse condensation via Hanbury Brown--Twiss correlations

TL;DR

This paper reports the experimental observation of transverse condensation in a Bose gas, demonstrating a phase where the gas condenses transversely while remaining thermal longitudinally, using Hanbury Brown--Twiss correlations.

Contribution

First experimental detection of transverse condensation in a Bose gas via Hanbury Brown--Twiss correlations, confirming a long-standing theoretical prediction.

Findings

Observation of the transition from 3D thermal gas to transverse condensate

Detection of transverse condensation using correlation measurements

Confirmation of theoretical predictions about lower-dimensional Bose gases

Abstract

A fundamental property of a three-dimensional Bose-Einstein condensate (BEC) is long-range coherence, however, in systems of lower dimensionality, not only is the long range coherence destroyed, but additional states of matter are predicted to exist. One such state is a `transverse condensate', first predicted by van Druten and Ketterle [Phys. Rev. Lett. 79, 549 (1997)], in which the gas condenses in the transverse dimensions of a highly anisotropic trap while remaining thermal in the longitudinal dimension. Here we detect the transition from a three-dimensional thermal gas to a gas undergoing transverse condensation by probing Hanbury Brown--Twiss correlations.