标题： 重杂质在费米气体中的质量间隙描述 显示英文标题

标题： Mass-gap description of heavy impurities in Fermi gases

摘要： 我们提出一个统一的理论，将移动杂质的费米极化子准粒子图景与静态杂质的安德森正交性灾难联系起来。 通过对底层多体哈密顿量的算符重新排列，我们得到一个修改后的费米子色散关系，该关系具有由反冲引起的能量间隙，我们称之为“质量间隙”。 我们表明，所得的平均场哈密顿量在有限杂质质量下表现出一个能带内态，这在费米极化子和分子形成中起着关键作用。 我们将质量间隙确定为费米极化子准粒子权重的微观起源，并推导出权重与杂质与费米子质量比的幂律标度。 相关能带内态被证明会导致极化子到分子转变的出现，而这种转变在安德森正交性灾难的极限情况下是不存在的。 显示英文摘要

摘要： We present a unified theory that connects the quasiparticle picture of Fermi polarons for mobile impurities to the Anderson orthogonality catastrophe for static impurities. By operator reordering of the underlying many-body Hamiltonian, we obtain a modified fermionic dispersion relation that features a recoil-induced energy gap, which we call the `mass gap'. We show that the resulting mean-field Hamiltonian exhibits an in-gap state for finite impurity mass, which takes a key role in Fermi polaron and molecule formation. We identify the mass gap as the microscopic origin of the quasiparticle weight of Fermi polarons and derive a power-law scaling of the weight with the impurity-to-fermion mass ratio. The associated in-gap state is shown to give rise to the emergence of the polaron-to-molecule transition away from the limiting case of the Anderson orthogonality catastrophe in which the transition is absent.