无间隙 Kitaev 自旋液体到张量网络的经典弦气。

Gapless Kitaev Spin Liquid to Classical String Gas through Tensor Networks.

机构信息

Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.

Department of Physics, University of Tokyo, Tokyo 113-0033, Japan.

出版信息

Phys Rev Lett. 2019 Aug 23;123(8):087203. doi: 10.1103/PhysRevLett.123.087203.

DOI:10.1103/PhysRevLett.123.087203

PMID:31491231

Abstract

We provide a framework for understanding the gapless Kitaev spin liquid (KSL) in the language of the tensor network (TN). Without introducing a Majorana fermion, most of the features of the KSL, including the symmetries, gauge structure, criticality, and vortex freeness, are explained in a compact TN representation. Our construction reveals a hidden string gas structure of the KSL. With only two variational parameters to adjust, we obtain an accurate KSL Ansatz with the bond dimension D=8 in a compact form, where the energy is about 0.007% higher than the exact one.

摘要

我们提供了一个用张量网络（TN）语言理解无能隙 Kitaev 自旋液体（KSL）的框架。在不引入马约拉纳费米子的情况下，我们用紧凑的 TN 表示解释了 KSL 的大部分特征，包括对称性、规范结构、临界性和无涡旋性。我们的构造揭示了 KSL 的隐藏弦气结构。通过仅调整两个变分参数，我们以紧凑的形式获得了具有 bond dimension D=8 的精确 KSL Ansatz，其中能量比精确值高约 0.007%。