论文标题
二维骨气和费米金超流体中的第一和第二声音
First and second sound in two-dimensional bosonic and fermionic superfluids
论文作者
论文摘要
我们回顾了有关超低效费原子和骨气原子的二维（2D）系统中声音传播的理论结果。在超氟阶段的特点是$ u（1）$对称性的自发对称性破坏，第一和第二声音的共存。在弱相互互动的排斥性玻色子的情况下，我们对以弱相互作用的态度以及Berezinskii-Kosterlitz-bkt-thouless（bkt）超级流动性过渡温度获得的2D的声速进行了建模。特别是，我们对超流体密度进行了非常准确的计算，并表明它与实验相当一致。对于超氟吸引人的费米，我们计算了整个BCS-BEC跨界的第一和第二声速度。在低温方案中，我们用6LI原子重现了最新的第一速速度测量值。我们还预测，只有在有限温度的BEC状态下，声音模式之间才有混合。
We review our theoretical results about the sound propagation in two-dimensional (2D) systems of ultracold fermionic and bosonic atoms. In the superfluid phase, characterized by the spontaneous symmetry breaking of the $U(1)$ symmetry, there is the coexistence of first and second sound. In the case of weakly-interacting repulsive bosons, we model the recent measurements of the sound velocities of 39K atoms in 2D obtained in the weakly-interacting regime and around the Berezinskii-Kosterlitz-Thouless (BKT) superfluid-to-normal transition temperature. In particular, we perform a quite accurate computation of the superfluid density and show that it is reasonably consistent with the experiment. For superfluid attractive fermions, we calculate the first and second sound velocities across the whole BCS-BEC crossover. In the low-temperature regime we reproduce the recent measurements of first-sound speed with 6Li atoms. We also predict that only in the finite-temperature BEC regime there is mixing between sound modes.
