Deng, Y (reprint author), Chinese Acad Sci, Inst Theoret Phys, State Key Lab Theoret Phys, POB 2735, Beijing 100190, Peoples R China.
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.