标题： 有限密度相互作用费米子的动量空间纠缠 显示英文标题

标题： Momentum-space entanglement for interacting fermions at finite density

摘要： 我们研究了一维有限密度相互作用相对论和非相对论费米子系统中单个场论模式之间的纠缠。 我们计算了单一场论模式的纠缠熵以及任意两个模式之间的互信息。 计算是在四费米子（两体）耦合的微扰展开中进行的，主要贡献出现在阶数 λ²log(λ²)。 在这个主导阶次上，当模式的动量接近费米面时，模式的纠缠熵的微扰表达式会发散成对数形式。 模式之间的互信息对于费米动量上下方附近的模式对来说最大。 如果通过截止场论来消除远离费米面的模式，那么靠近费米面的模式的纠缠性质在定性上是相同的。 显示英文摘要

摘要： We investigate the entanglement between individual field theory modes in finite-density systems of interacting relativistic and non-relativistic fermions in one spatial dimension. We calculate the entanglement entropy for a single field theory mode and the mutual information between any two modes. The calculation is perturbative in the four-fermion (two-body) coupling, with the leading contribution at order lambda^2 log(lambda^2). At this leading order, the perturbative expression for the entanglement entropy of a mode diverges logarithmically as the momentum of the mode approaches the Fermi surface from above or below. The mutual information between modes is largest for pairs of modes just above and below the Fermi momentum. The entanglement properties of modes near the Fermi surface are qualitatively the same if the field theory is cut off to eliminate modes away from the Fermi surface.