论文标题
量子场理论中激发态的对称纠缠II:数字,相互作用的理论和更高的维度
Symmetry Resolved Entanglement of Excited States in Quantum Field Theory II: Numerics, Interacting Theories and Higher Dimensions
论文作者
论文摘要
在最近的一篇论文中,我们研究了复杂自由量子场理论中零密度激发态的纠缠含量,重点是对称性解决的纠缠熵(SREE)。通过零密度状态,我们的意思是由无限体积系统中固定数量的激发量组成的状态。 Sree定义为具有内部对称性的理论,并提供了对每个对称部门总纠缠的贡献的量度。在我们的工作中,我们表明,SREES的傅立叶转变(即带电矩的比率)对这些状态采用非常简单且通用的形式,这仅取决于激发的数量,统计和对称性电荷以及纠缠区域的相对大小与整个系统的大小相对。在本文中,我们通过在两种自由晶格理论中计算带电矩的功能来为我们的公式提供数值证据:一维费米气体和复杂的谐波链。我们还向两个方向扩展了结果:通过证明它们也适用于相互作用理论的激发态(即镁态),并通过开发对分支点扭曲场图的更高维度的概括,从而导致(相互作用)高维模型。
In a recent paper we studied the entanglement content of zero-density excited states in complex free quantum field theories, focusing on the symmetry resolved entanglement entropy (SREE). By zero-density states we mean states consisting of a fixed, finite number of excitations above the ground state in an infinite-volume system. The SREE is defined for theories that possess an internal symmetry and provides a measure of the contribution to the total entanglement of each symmetry sector. In our work, we showed that the ratio of Fourier-transforms of the SREEs (i.e. the ratio of charged moments) takes a very simple and universal form for these states, which depends only on the number, statistics and symmetry charge of the excitations as well as the relative size of the entanglement region with respect to the whole system's size. In this paper we provide numerical evidence for our formulae by computing functions of the charged moments in two free lattice theories: a 1D Fermi gas and a complex harmonic chain. We also extend our results in two directions: by showing that they apply also to excited states of interacting theories (i.e. magnon states) and by developing a higher dimensional generalisation of the branch point twist field picture, leading to results in (interacting) higher-dimensional models.