Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands.
Phys Rev Lett. 2013 Nov 22;111(21):215301. doi: 10.1103/PhysRevLett.111.215301. Epub 2013 Nov 19.
We show that a Bose-Einstein condensate of heteronuclear molecules in the regime of small and static electric fields is described by a quantum rotor model for the macroscopic electric dipole moment of the molecular gas cloud. We solve this model exactly and find the symmetric, i.e., rotationally invariant, and dipolar phases expected from the single-molecule problem, but also an axial and planar nematic phase due to many-body effects. Investigation of the wave function of the macroscopic dipole moment also reveals squeezing of the probability distribution for the angular momentum of the molecules.
我们表明，在小电场和静态电场的条件下，异核分子的玻色-爱因斯坦凝聚态可以用分子气体云的宏观电偶极矩的量子转子模型来描述。我们精确地求解了这个模型，发现了从单分子问题中预期的对称，即旋转不变的，和偶极相，也发现了由于多体效应导致的轴向和平面向列相。对宏观电偶极矩的波函数的研究也揭示了分子角动量的概率分布的压缩。
