arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0909.3031cond-mat.stat-mechcond-mat.str-el
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具有破缺序的双不变量子晶格系统序参量的普适构造

Universal construction of order parameters for translation-invariant quantum lattice systems with symmetry-breaking order

Jin-Hua Liu, Qian-Qian Shi, Hong-Lei Wang, Jon Links, Huan-Qiang Zhou

摘要:

对于任意对称群为G的量子晶格系统,我们提出了一种实用的、通用的序参量的构造方法,用以识别具有破缺序的量子相变.它们被定义在基态和它的量子变换对应物之间的保真度方面,并且通过基态波函数的张量网络表示来计算。为了说明我们的方案,我们考虑了一维无限晶格上的三个量子系统,即横向磁场中的量子伊辛模型、外磁场中的量子自旋1/2 Xyx模型和单离子各向异性的量子自旋1 XXZ模型.这些模型都具有对称群Z_2,并呈现对称性破缺相。我们还讨论了序参量在确定因子化态中的作用。

英文摘要:

For any translation-invariant quantum lattice system with a symmetry group G, we propose a practical and universal construction of order parameters which identify quantum phase transitions with symmetry-breaking order. They are defined in terms of the fidelity between a ground state and its symmetry-transformed counterpart, and are computed through tensor network representations of the ground-state wavefunction. To illustrate our scheme, we consider three quantum systems on an infinite lattice in one spatial dimension, namely, the quantum Ising model in a transverse magnetic field, the quantum spin-1/2 XYX model in an external magnetic field, and the quantum spin-1 XXZ model with single-ion anisotropy. All these models have symmetry group Z_2 and exhibit broken-symmetry phases. We also discuss the role of the order parameters in identifying factorized states.

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。

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