Single-particle excitations in a trapped gas of Fermi atoms in the BCS-BEC crossover region. II. Broad Feshbach resonance
Single-particle excitations in a trapped gas of Fermi atoms in the BCS-BEC crossover region. II. Broad Feshbach resonance
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DOI：
10.1103/physreva.72.013601
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发表时间：
2004-10
影响因子：
2.9
通讯作者：
Y. Ohashi;A. Griffin
中科院分区：
文献类型：
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作者：
Y. Ohashi;A. Griffin
我们应用在最近的论文[Y. Ohashi和A. Griffin，Phys.Rev.A72，013601（2005）]中的BCS-BEC交叉中的单粒子激发到宽Feshbach共振的情况。在T=0时，我们求解Bogoliubov-de Gennes耦合方程，同时考虑束缚态（分子）的玻色凝聚。在宽共振的情况下，密度分布n（r）以及超流序参数{delta}-波浪线（r）的分布在空间上扩展到高斯-费米半径，甚至在交叉区域中。该序参数{delta}-代字号（r）抑制了低能Andreev束缚态对rf隧穿电流的影响。其结果是，在射频频谱中的峰值能量被发现发生在能量等于超流序参数{delta}-代字号（r=0）在中心的陷阱，在一个狭窄的共振的情况下，并与最近的测量结果一致。局域密度近似被认为是一个很好的近似的射频隧穿谱。
We apply the formulation developed in a recent paper [Y. Ohashi and A. Griffin, Phys. Rev. A 72, 013601 (2005)] for single-particle excitations in the BCS-BEC crossover to the case of a broad Feshbach resonance. At T=0, we solve the Bogoliubov-de Gennes coupled equations taking into account a Bose condensate of bound states (molecules). In the case of a broad resonance, the density profile n(r), as well as the profile of the superfluid order parameter {delta}-tilde(r), are spatially spread out to the Thomas-Fermi radius, even in the crossover region. This order parameter {delta}-tilde(r) suppresses the effects of low-energy Andreev bound states on the rf tunneling current. As a result, the peak energy in the rf spectrum is found to occur at an energy equal to the superfluid order parameter {delta}-tilde(r=0) at the center of the trap, in contrast to the case of a narrow resonance, and in agreement with recent measurements. The local density approximation is found to give a good approximation for the rf-tunneling spectrum.