论文标题
互动费米子的动量空间纠缠
Momentum space entanglement of interacting fermions
论文作者
论文摘要
动量空间纠缠熵探针在相互作用的费米子阶段中的量子相关性。它对相互作用非常敏感，在费米气体中消失的同时，遵守体积法的缩放。我们表明，动量空间中的rényi熵在分区的相空体积方面具有系统的扩展，该分区的相位体积在扰动理论中的所有顺序都符合。例如，这允许在各向同性费米液体和BCS超导体中Fermi波形附近的细壳的熵进行受控计算。在费米液体中，薄壳熵是准颗粒残基的通用功能。在超导体中，它反映了库珀对的形成。通过对先前实施的测量方案的飞行时间概括，在冷原子和分子气体实验中可以访问动量空间。
Momentum space entanglement entropy probes quantum correlations in interacting fermionic phases. It is very sensitive to interactions, obeying volume-law scaling in general, while vanishing in the Fermi gas. We show that the Rényi entropy in momentum space has a systematic expansion in terms of the phase space volume of the partition, which holds at all orders in perturbation theory. This permits, for example, the controlled computation of the entropy of thin shells near the Fermi wavevector in isotropic Fermi liquids and BCS superconductors. In the Fermi liquid, the thin shell entropy is a universal function of the quasiparticle residue. In the superconductor, it reflects the formation of Cooper pairs. Momentum space Rényi entropies are accessible in cold atomic and molecular gas experiments through a time-of-flight generalization of previously implemented measurement protocols.
