标题： 重费米子极化子在BCS费米超流体中的精确准粒子性质 显示英文标题

标题： Exact quasiparticle properties of a heavy polaron in BCS Fermi superfluids

摘要： 我们通过精确的函数行列式方法，展示了重杂质在相互作用费米超流体中的拉姆齐响应和射频光谱。 我们通过传统的巴丁-库珀-施里弗理论描述费米超流体，并研究配对间隙在两种光谱揭示的准粒子特性中的作用。 成对破坏的能量成本阻止了非相互作用费米气体中出现的安德森\textquoteright 的正交性灾难，并允许在精确可解的重杂质极限下存在极化子准粒子。 因此，我们严格确认了诸如暗连续谱、分子空穴连续谱和排斥极化子等显著特征。 对于有限温度下磁性杂质的散射，我们预测了与亚能隙 Yu-Shiba-Rusinov 束缚态相关的额外共振，其位置可用于测量超流配对间隙。 对于零温度下的非磁性散射，我们意外地发现无阻尼的排斥极化子。 这些精确结果可能在具有大质量比的玻色-费米混合物的量子气体实验中轻易观察到。 显示英文摘要

摘要： We present the Ramsey response and radio-frequency spectroscopy of a heavy impurity immersed in an interacting Fermi superfluid, using exact functional determinant approach. We describe the Fermi superfluid through the conventional Bardeen-Cooper-Schrieffer theory and investigate the role of the pairing gap on quasiparticle properties revealed by the two spectroscopies. The energy cost for pair breaking prevents Anderson\textquoteright s orthogonality catastrophe that occurs in a non-interacting Fermi gas and allows the existence of polaron quasiparticles in the exactly solvable heavy impurity limit. Hence, we rigorously confirm the remarkable features such as dark continuum, molecule-hole continuum and repulsive polaron. For a magnetic impurity scattering at finite temperature, we predict additional resonances related to the sub-gap Yu-Shiba-Rusinov bound state, whose positions can be used to measure the superfluid pairing gap. For a non-magnetic scattering at zero temperature, we surprisingly find undamped repulsive polarons. These exact results might be readily observed in quantum gas experiments with Bose-Fermi mixtures that have a large-mass ratio.