Interaction-induced anomalous quantum Hall state on the honeycomb lattice
Interaction-induced anomalous quantum Hall state on the honeycomb lattice
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DOI：
10.1103/physrevb.89.165123
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发表时间：
2014-01
影响因子：
3.7
通讯作者：
T. Durić;N. Chancellor;I. Herbut
中科院分区：
文献类型：
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作者：
T. Durić;N. Chancellor;I. Herbut
马克斯普朗克物理复杂系统研究所，Nothnitzer Str。 38, 01187 德国德累斯顿（日期：2014年1月23日）我们研究了蜂窝晶格上相互作用产生的量子反常霍尔相的存在性。对于半填充时的无自旋模型，使用平均场方法预测了量子反常霍尔相（陈绝缘体相）的存在。然而，最近对具有周期性边界条件的小团簇的精确对角化研究尚未发现相互作用驱动的陈绝缘体相的明显迹象。我们使用精确对角化方法来研究具有开放边界条件的小团簇的性质，并且与之前的研究相反，我们发现了有限尺寸团簇的拓扑相变的清晰特征。我们还研究了纠缠斑块态（相关器积态） ansatz 的适用性来描述系统的基态。在这种方法中，晶格被小片覆盖，基态波函数用小片系数来表示。然后可以使用变分蒙特卡罗算法来优化配置权重。使用纠缠斑块状态，我们研究了较大系统尺寸的系统的基态特性，并表明结果与小团簇的精确对角化结果一致。这证实了纠缠板态模拟描述系统基态的有效性，并进一步证实了平均场理论计算所预测的热力学极限中量子反常霍尔相的存在。
Max-Planck-Institut fur Physik Komplexer Systeme, Nothnitzer Str. 38, 01187 Dresden, Germany(Dated: January 23, 2014)We examine the existence of the interaction-generated quantum anomalous Hall phase on thehoneycomb lattice. For the spinless model at half filling, the existence of a quantum anomalous Hallphase (Chern insulator phase) has been predicted using mean-field methods. However, recent exactdiagonalization studies for small clusters with periodic boundary condition have not found a clearsign of an interaction-driven Chern insulator phase. We use exact diagonalization method to studyproperties of small clusters with open boundary condition and, contrary to previous studies, we findclear signatures of the topological phase transition for finite size clusters. We also examine appli-cability of the entangled-plaquette state (correlator-product state) ansatz to describe the groundstates of the system. Within this approach the lattice is covered with plaquettes and the groundstate wave-function is written in terms of the plaquette coefficients. Configurational weights canthen be optimized using a variational Monte Carlo algorithm. Using the entangled-plaquette stateansatz we study the ground state properties of the system for larger system sizes and show that theresults agree with the exact diagonalization results for small clusters. This confirms validity of theentangled-plaquette state ansatz to describe the ground states of the system and provides furtherconfirmation of the existence of the quantum anomalous Hall phase in the thermodynamic limit, aspredicted by the mean-field theory calculations.