Spin fragmentation of Bose–Einstein condensates with antiferromagnetic interactions
Spin fragmentation of Bose–Einstein condensates with antiferromagnetic interactions
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DOI：
10.1088/1367-2630/15/11/113039
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发表时间：
2013-07
影响因子：
3.3
通讯作者：
L. D. Sarlo;L. Shao;V. Corre;T. Zibold;D. Jacob;J. Dalibard;F. Gerbier
中科院分区：
文献类型：
--
作者：
L. D. Sarlo;L. Shao;V. Corre;T. Zibold;D. Jacob;J. Dalibard;F. Gerbier
We study spin fragmentation of an antiferromagnetic spin 1 condensate in the presence of a quadratic Zeeman (QZ) effect breaking spin rotational symmetry. We describe how the QZ effect turns a fragmented spin state, with large fluctuations of the Zeeman populations, into a regular polar condensate, where the atoms all condense in the m = 0 state along the field direction. We calculate the average value and variance of the population of the Zeeman state m = 0 to illustrate clearly the crossover from a fragmented to an unfragmented state. The typical width of this crossover is q ∼ kBT/N, where q is the QZ energy, T the spin temperature and N the atom number. This shows that the spin fluctuations are a mesoscopic effect that will not survive in the thermodynamic limit N → ∞, but are observable for a sufficiently small atom number.
