Pair correlations of an expanding superfluid fermi gas

被引:30
作者
Lobo, C. [1 ]
Carusotto, I.
Giorgini, S.
Recati, A.
Stringari, S.
机构
[1] Univ Trent, Dipartimento Fis, I-38050 Trento, Italy
[2] CNR, INFM, BEC Ctr, I-38050 Trento, Italy
关键词
D O I
10.1103/PhysRevLett.97.100405
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
The pair correlation function of an expanding gas is investigated with an emphasis on the BEC-BCS crossover of a superfluid Fermi gas at zero temperature. At unitarity quantum Monte Carlo simulations reveal the occurrence of a sizable bunching effect due to interactions in the spin up-down channel which, at short distances, is larger than that exhibited by thermal bosons in the Hanbury-Brown-Twiss effect. We propose a local equilibrium ansatz for the pair correlation function which we predict will remain isotropic during the expansion even if the trapping potential is anisotropic, in contrast with the behavior of the density. The isotropy of the pair correlation function is an experimentally accessible signature, which makes a clear distinction with respect to the case of noninteracting gases and can be understood as a consequence of the violation of scaling.
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页数:4
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