Dynamic structure factors of a strongly interacting Fermi superfluid near an orbital Feshbach resonance across the phase transition from BCS to Sarma superfluid
Dynamic structure factors of a strongly interacting Fermi superfluid near an orbital Feshbach resonance across the phase transition from BCS to Sarma superfluid
复制标题
强相互作用费米超流体在从 BCS 到 Sarma 超流体相变过程中轨道费什巴赫共振附近的动态结构因素
DOI：
10.1103/physreva.103.053310
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发表时间：
2021
影响因子：
2.9
通讯作者：
Hu Hui
中科院分区：
文献类型：
--
作者：
Zou Peng;Zhao Huaisong;He Lianyi;Liu Xia-Ji;Hu Hui
在无规相位近似下，研究了轨道Feshbach共振附近强相互作用Fermi超流体的动力学结构因子，并通过连续改变两个自旋分量的化学势差，得到了平衡的常规Bardeen-Cooper-Schrieffer超流体与极化的Sarma超流体相变过程中的动力学特征.在BCS超流体的类BEC体系中，动力学结构因子可以通过分子激发和Leggett模的相对位置，或破坏库珀对的最小能量来区分同相基态和异相亚稳态.在BCS和Sarma超流体的相变过程中，我们发现Sarma超流体的动力学结构因子在小转移动量时具有自己特有的无隙激发，这种激发与集体声子激发混合，在大转移动量时由于存在未成对的费米原子，也具有相对较强的原子激发，这些信号可以用来区分Sarma超流体和BCS超流体。
We theoretically investigate dynamic structure factors of a strongly interacting Fermi superfluid near an orbital Feshbach resonance with random phase approximation, and find their dynamical characters during the phase transition between a balanced conventional Bardeen-Cooper-Schrieffer superfluid and a polarized Sarma superfluid by continuously varying the chemical potential difference of two spin components. In a BEC-like regime of the BCS superfluid, dynamic structure factors can do help to distinguish the in-phase ground state from the out-of-phase metastable state by the relative location of molecular excitation and Leggett mode, or the minimum energy to break a Cooper pair. In the phase transition between BCS and Sarma superfluid, we find the dynamic structure factor of Sarma superfluid has its own specific gapless excitation at a small transferred momentum which is mixed with the collective phonon excitation, and also a relatively strong atomic excitation at a large transferred momentum because of the existence of unpaired Fermi atoms, these signals can be used to differentiate Sarma superfluid from BCS superfluid.