Crystallized and amorphous vortices in rotating atomic-molecular Bose-Einstein condensates

Chao-Fei Liu,Shih-Chuan Gou,Wu-Ming Liu,Heng Fan

doi:10.1038/srep04224

Abstract

Vortex is a topological defect with a quantized winding number of the phase in superfluids and superconductors. Here, we investigate the crystallized (triangular, square, honeycomb) and amorphous vortices in rotating atomic-molecular Bose-Einstein condensates (BECs) by using the damped projected Gross-Pitaevskii equation. The amorphous vortices are the result of the considerable deviation induced by the interaction of atomic-molecular vortices. By changing the atom-molecule interaction from attractive to repulsive, the configuration of vortices can change from an overlapped atomic-molecular vortices to carbon-dioxide-type ones, then to atomic vortices with interstitial molecular vortices, and finally into independent separated ones. The Raman detuning can tune the ratio of the atomic vortex to the molecular vortex. We provide a phase diagram of vortices in rotating atomic-molecular BECs as a function of Raman detuning and the strength of atom-molecule interaction.

Highlights

Vortex is a topological defect with a quantized winding number of the phase in superfluids and superconductors
To the normal system of twocomponent BECs5, a phase diagram of vortices in rotating atomic-molecular Bose-Einstein condensates (BECs) is required to provide a full realization of the nontrivial vortex phenomenon
The phase diagram indicates that atom-molecule interaction can control the atomic-molecular vortices to suffer a dramatic dissociation transition from an overlapped atomic-molecular vortices with interlaced www.nature.com/scientificreports molecular vortices to the carbon-dioxide-type atomic-molecular vortices, to the atomic vortices with interstitial molecular vortices, and to the completely separated atomic-molecular vortices

Summary

Introduction

Vortex is a topological defect with a quantized winding number of the phase in superfluids and superconductors. It is shown recently that the coherent coupling can render a pairing of atomic and molecular vortices into a composite structure that resembles a carbon dioxide molecule[17] Considering both attractive and repulsive atom-molecule interaction, Woo et al have explored the structural phase transition of atomic-molecular vortex lattices by increasing the rotating frequency. The phase diagram indicates that atom-molecule interaction can control the atomic-molecular vortices to suffer a dramatic dissociation transition from an overlapped atomic-molecular vortices with interlaced www.nature.com/scientificreports molecular vortices to the carbon-dioxide-type atomic-molecular vortices, to the atomic vortices with interstitial molecular vortices, and to the completely separated atomic-molecular vortices This result is in accordance with the predicted dissociation of the composite vortex lattice in the flux-flow of two-band superconductors[39]. This study shows a full picture about the vortex state in rotating atomic-molecular BECs

Methods

Results

Conclusion