论文标题
与自旋轨道耦合的一维费米超流体的动态结构因子
Dynamic structure factor of one-dimensional Fermi superfluid with spin-orbit coupling
论文作者
论文摘要
我们从理论上计算使用拉曼型自旋轨道耦合的一维费米超流体的密度动态结构因子，并分析其在Bardeen-Cooper-Schrieffer超级流体和拓扑超级流体之间的相变时其主要动力学特征。我们的理论结果显示了由单粒子光谱的两分支结构引起的四种单粒子激发，并且在较小的传递动量下，在自旋动态结构因子中可以看到交叉单粒子激发。另外，我们发现新的类似Roton的集体模式出现在固定的转移动量$ Q \ simeq 2K_F $上，并且仅在系统进入拓扑超流体状态后才出现。这种类似Roton的激发的发生与单粒子光谱中的全局最小值从$ k = 0 $转换为$ k \ simeq 2k_f $有关。
We theoretically calculate the density dynamic structure factor of one-dimensional Fermi superfluid with Raman-type spin-orbit coupling, and analyze its main dynamical character during phase transition between Bardeen-Cooper-Schrieffer superfluid and topological superfluid. Our theoretical results display four kinds of single-particle excitations induced by the two-branch structure of single-particle spectrum, and the cross single-particle excitation is much easier to be seen in the spin dynamic structure factor at a small transferred momentum. Also we find a new roton-like collective mode emerges at a fixed transferred momentum $q \simeq 2k_F$, and it only appears once the system enters the topological superfluid state. The occurrence of this roton-like excitation is related to switch of global minimum in single-particle spectrum from $k=0$ to $k \simeq 2k_F$.
