标题： Rabi耦合的二元玻色-爱因斯坦凝聚体中的反常超流 显示英文标题

标题： Rabi-coupled Countersuperflow in Binary Bose-Einstein Condensates

摘要： 我们从理论上展示了，在Rabi耦合下，两个反向传播的处于不同超精细态的玻色-爱因斯坦凝聚体中的周期性密度图案是稳定的。 在耦合存在的情况下，两个组分之间的相对速度在准一维系统中被局域在密度降低区域附近。 当相对速度足够小时，周期性图案会减少为相对相位的奇点的周期性孤子阵列。 根据我们的变分和数值分析，孤子解由孤子宽度和密度降低很好地表征。 我们展示了密度降低和宽度对Rabi频率以及组分间密度-密度相互作用耦合常数的依赖关系。 当周期小于孤子宽度时，相对相位的周期性图案连续地从孤子阵列转变为正弦波图案。 当局域的相对速度超过临界值时，这些图案变得不稳定。 通过考虑由于密度降低引起的有限尺寸效应，对该系统的稳定性相图进行了稳定性分析。 显示英文摘要

摘要： We show theoretically that periodic density patterns are stabilized in two counter-propagating Bose-Einstein condensates of atoms in different hyperfine states under Rabi coupling. In the presence of coupling, the relative velocity between two components is localized around density depressions in quasi-one-dimensional systems. When the relative velocity is sufficiently small, the periodic pattern reduces to a periodic array of topological solitons as kinks of relative phase. According to our variational and numerical analyses, the soliton solution is well characterized by the soliton width and density depression. We demonstrate the dependence of the depression and width on the Rabi frequency and the coupling constant of inter-component density-density interactions. The periodic pattern of the relative phase transforms continuously from a soliton array to a sinusoidal pattern as the period becomes smaller than the soliton width. These patterns become unstable when the localized relative velocity exceeds a critical value. The stability-phase diagram of this system is evaluated with a stability analysis of countersuperflow, by taking into account the finite-size-effect owing to the density depression.