The Bose-Einstein Condensate of G-wave Molecules and Its Intrinsic Angular Momentum

TL;DR

This paper reports the creation of a Bose-Einstein condensate of G-wave molecules with intrinsic angular momentum, revealing new quantum effects and potential for probing unique excitations in molecular condensates.

Contribution

It demonstrates the first BEC of G-wave molecules with intrinsic angular momentum and explores its implications for quantum phenomena and excitations.

Findings

Observation of reduced three-body loss at G-wave resonance in quasi-2D

Detection of collective mode splitting without vortices

Identification of angular momentum effects in non-uniform magnetic fields

Abstract

The recent report on the realization of a Bose-Einstein condensate of G-wave molecule made up of bound pairs of Cesium bosons is a surprise. These molecules are created at the G-wave resonance at 19.87G, where the severe three-body loss usually associated with these resonance are found to be reduced significantly when the density of the gas is reduced in a quasi 2D setting. The G-wave molecules produced through this resonance have non-zero angular momentum projections, resulting in the first BEC with a macroscopic intrinsic angular momentum. Here, we show that this intrinsic angular momentum will lead to many new quantum effects. They include a splitting of collective modes in the absence of vortices, an orientation dependent energy shift due to the moment of inertia of the molecules, and a contribution to angular momentum in non-uniform magnetic fields different from that of the Berry phase current. The intrinsic angular momentum also provides a way to probe the half vortices, excitations that are unique to molecular condensates of bosons. The wavefunction giving rise to the intrinsic angular momentum can also be mapped out from the noise correlation.