Nematic order by disorder in spin-2 Bose-Einstein condensates.
Nematic order by disorder in spin-2 Bose-Einstein condensates.
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DOI：
10.1103/physrevlett.98.190404
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发表时间：
2007-05
影响因子：
8.6
通讯作者：
A. Turner;R. Barnett;E. Demler;A. Vishwanath
中科院分区：
文献类型：
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作者：
A. Turner;R. Barnett;E. Demler;A. Vishwanath
我们证明了自旋 2 玻色-爱因斯坦凝聚中的量子和热涨落提升了平均场相图的意外简并性。对于散射长度 a4>a2 (a4<a2)，涨落选择单轴（方形双轴）向列态。矛盾的是，温度越高，有序性就越强。对于 spin-2 87Rb 和 23Na，预测在增强磁场时会发生连续的伊辛型转变，从涨落稳定的单轴态到场稳定的方形双轴有序态。这是一个很有前途的实验系统，可以实现“有序-无序”现象。
We show that quantum and thermal fluctuations in spin-2 Bose-Einstein condensates lift the accidental degeneracy of the mean-field phase diagram. Fluctuations select the uniaxial (square biaxial) nematic state for scattering lengths a4>a2 (a4<a2). Paradoxically, the order is stronger at higher temperatures. For spin-2 87Rb and 23Na, a continuous Ising-type transition is predicted on raising the magnetic field, from a fluctuation stabilized uniaxial state to a field stabilized square biaxial order state. This is a promising experimental system to realize the "order-by-disorder" phenomenon.