Spinor Bose-Einstein Condensates of Rotating Polar Molecules

TL;DR

This paper proposes a method to realize and study spinor Bose-Einstein condensates of rotating polar molecules, revealing tunable interactions and novel quantum phases such as vortex states in ultracold molecular gases.

Contribution

It introduces a scheme to create a pseudospin-1/2 model with tunable dipole interactions and explores the resulting quantum phases in molecular condensates.

Findings

Tunable dipole-dipole interactions via microwave fields.

Discovery of nontrivial quantum phases including vortex states.

Potential to extend to spin-1 models of polar molecules.

Abstract

We propose a scheme to realize a pseudospin-$1/2$ model of the $^{1}\Sigma(v=0)$ bialkali polar molecules with the spin states corresponding to two sublevels of the first excited rotational level. We show that the effective dipole-dipole interaction between two spin-$1/2$ molecules couples the rotational and orbital angular momenta and is highly tunable via a microwave field. We also investigate the ground state properties of a spin-$1/2$ molecular condensate. A variety of nontrivial quantum phases, including the doubly-quantized vortex states, are discovered. Our scheme can also be used to create spin-$1$ model of polar molecules. Thus, we show that the ultracold gases of bialkali polar molecules provide a unique platform for studying the spinor condensates of rotating molecules.