论文标题
间隔的Schwinger模型：分析结果和DMRG
Schwinger model on an interval: analytic results and DMRG
论文作者
论文摘要
$ 1+1 $尺寸（Schwinger模型）的量子电动力学在间隔中以有限维的Hilbert空间进行晶格离散化，并且经常用作量子和张量网络模拟的测试平台。在这项工作中，我们阐明了连续体和晶格理论中边界条件之间的精确映射。特别是，我们表明，模拟中常用的常规高斯定律约束会引起对电荷密度的强大影响，这反映了分数化电荷的外观。此外，我们通过琼脂化获得了许多精确的分析结果，可为无质量的雪松模型中的局部观察结果获得。我们将这些分析结果与通过密度基质重新归一化组（DMRG）方法获得的仿真结果进行了比较，并找到了出色的协议。
Quantum electrodynamics in $1+1$ dimensions (Schwinger model) on an interval admits lattice discretization with a finite-dimensional Hilbert space, and is often used as a testbed for quantum and tensor network simulations. In this work we clarify the precise mapping between the boundary conditions in the continuum and lattice theories. In particular we show that the conventional Gauss law constraint commonly used in simulations induces a strong boundary effect on the charge density, reflecting the appearance of fractionalized charges. Further, we obtain by bosonization a number of exact analytic results for local observables in the massless Schwinger model. We compare these analytic results with the simulation results obtained by the density matrix renormalization group (DMRG) method and find excellent agreements.
