Quantum Spin Liquid Phase in the Shastry–Sutherland Model Detected by an Improved Level Spectroscopic Method

作     者：Ling Wang Yalei Zhang Anders W.Sandvik Ling Wang;Yalei Zhang;Anders W.Sandvik

作者机构：Department of PhysicsZhejiang UniversityHangzhou 310000China Beijing Computational Science Research CenterBeijing 100193China Department of PhysicsBoston UniversityBostonMassachusetts 02215USA Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2022年第39卷第7期

页      面：105-116页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0714[理学-统计学（可授理学、经济学学位）] 0701[理学-数学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 11874080 and 11734002) supported as a Simons Investigator by the Simons Foundation (Grant No. 511064) 

主　　题：red SSM Sutherland Model Detected by an Improved Level Spectroscopic Method Quantum Spin Liquid Phase in the Shastry Model 

摘      要：We study the spin-1/2 two-dimensional Shastry–Sutherland spin model by exact diagonalization of clusters with periodic boundary conditions, developing an improved level spectroscopic technique using energy gaps between states with different quantum numbers. The crossing points of some of the relative(composite) gaps have much weaker finite-size drifts than the normally used gaps defined only with respect to the ground state, thus allowing precise determination of quantum critical points even with small clusters. Our results support the picture of a spin liquid phase intervening between the well-known plaquette-singlet and antiferromagnetic ground states, with phase boundaries in almost perfect agreement with a recent density matrix renormalization group study, where much larger cylindrical lattices were used [J. Yang et al., Phys. Rev. B 105, L060409(2022)]. The method of using composite low-energy gaps to reduce scaling corrections has potentially broad applications in numerical studies of quantum critical phenomena.