论文标题
两个重型费米极性的散射：共振和quasibound状态
Scattering of two heavy Fermi polarons: resonances and quasibound states
论文作者
论文摘要
费米海或费米极化物中的杂质经历了介质量子波动引起的casimir相互作用。当杂质和费米子之间存在短距离的吸引力时，在短距离上，诱导的两种杂质之间的相互作用也很有吸引力，并且在空间中振荡较大的距离。从理论上讲，我们研究了散射特性，并计算理想的费米气体在零温度下的散射相移和散射长度和散射长度。尽管杂质之间的诱导相互作用对于弱杂质中的相互作用而言是弱吸引人的，但我们发现杂质在诱导的散射中与培养基的共振强烈而有吸引力的相互作用，并且诱导的散射长度的标志变化，甚至强烈的排斥。每当三体Efimov结合状态出现在连续阈值处时，这些共振就会发生。在连续阈值以上的能量下，我们发现介质中的Efimov状态可以变成具有有限衰减宽度的准状态。
Impurities in a Fermi sea, or Fermi polarons, experience a Casimir interaction induced by quantum fluctuations of the medium. When there is short-range attraction between impurities and fermions, also the induced interaction between two impurities is strongly attractive at short distance and oscillates in space for larger distances. We theoretically investigate the scattering properties and compute the scattering phase shifts and scattering lengths between two heavy impurities in an ideal Fermi gas at zero temperature. While the induced interaction between impurities is weakly attractive for weak impurity-medium interactions, we find that impurities strongly and attractively interacting with the medium exhibit resonances in the induced scattering with a sign change of the induced scattering length and even strong repulsion. These resonances occur whenever a three-body Efimov bound state appears at the continuum threshold. At energies above the continuum threshold, we find that the Efimov state in medium can turn into a quasibound state with a finite decay width.
