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arXiv 0909.5481cond-mat.str-el
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拓扑绝缘体的量子相变

Quantum Phase Transitions of Topological Insulators

Lan-Feng Liu, Su-Peng Kou

摘要:

本文从拓扑绝缘体的晶格模型出发,通过计算不同量子态(量子自旋霍尔态、量子反常霍尔态和正常带绝缘体态)的拓扑性质(边缘态、量子自旋霍尔电导率和π通量上零模的个数),研究了它们之间的量子相变.我们发现拓扑量子相变在不同情况下存在着普遍的特征:高对称点节点费米子的出现、基态能量的非解析三阶导数和拓扑“序参量“的跳跃.特别是,TQPT和系统的对称性之间的关系进行了探索:不同的TQPT的保护不同的(整体)对称性,然后描述不同的拓扑“序参量“。

英文摘要:

In this paper, starting from a lattice model of topological insulators, we study the quantum phase transitions among different quantum states, including quantum spin Hall state, quantum anomalous Hall state and normal band insulator state by calculating their topological properties (edge states, quantized spin Hall conductivities and the number of zero mode on a Pi-flux). We find that there exist universal features for the topological quantum phase transitions (TQPTs) in different cases : the emergence of nodal fermions at high symmetry points, the non-analytic third derivative of ground state energy and the jumps of the topological "order parameters". In particular, the relation between TQPTs and symmetries of the systems are explored : different TQPTs are protected by different (global) symmetries and then described by different topological "order parameters".

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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