arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2004.10606cond-mat.stat-mechhep-th
收藏

量子XY自旋链中形成几率和普适边界熵的标度

Scaling of the Formation Probabilities and Universal Boundary Entropies in the Quantum XY Spin Chain

Filiberto Ares, M. A. Rajabpour, Jacopo Viti

摘要:

在横向$σ^z$基下,我们精确地计算了XY链在给定自旋组态下找到基态的几率。通过确定有限体积修正的各种配置的概率,我们得到了在临界点的通用边界熵。后者是表征每个量子态的基本边界共形场论的基准。为了确定比例的概率,我们证明了一个定理,表示,在一个因式分解的形式,一个循环矩阵的子矩阵的特征值的函数的原始矩阵的特征值。最后,边界熵计算利用推广的欧拉-麦克劳林公式不可微功能。结果表明,在某些情况下,自旋组态可以流到Cardy态的线性叠加。我们的方法和工具是相当通用的,可以适用于所有的周期量子链映射到自由费米子哈密顿。

英文摘要:

We calculate exactly the probability to find the ground state of the XY chain in a given spin configuration in the transverse $σ^z$-basis. By determining finite-volume corrections to the probabilities for a wide variety of configurations, we obtain the universal Boundary Entropy at the critical point. The latter is a benchmark of the underlying Boundary Conformal Field Theory characterizing each quantum state. To determine the scaling of the probabilities, we prove a theorem that expresses, in a factorized form, the eigenvalues of a sub-matrix of a circulant matrix as functions of the eigenvalues of the original matrix. Finally, the Boundary Entropies are computed by exploiting a generalization of the Euler-MacLaurin formula to non-differentiable functions. It is shown that, in some cases, the spin configuration can flow to a linear superposition of Cardy states. Our methods and tools are rather generic and can be applied to all the periodic quantum chains which map to free-fermionic Hamiltonians.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑