Valley Chern numbers and boundary modes in gapped bilayer graphene
Valley Chern numbers and boundary modes in gapped bilayer graphene
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DOI：
10.1073/pnas.1308853110
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发表时间：
2013-01
期刊：
影响因子：
--
通讯作者：
Fan Zhang;A. Macdonald;E. Mele
中科院分区：
文献类型：
--
作者：
Fan Zhang;A. Macdonald;E. Mele
通过分析它们的四带和两带连续模型，通过对晶格进行数值计算，并通过使用量子几何参数，研究了双层石墨烯中畴壁的电子态。连续介质理论解释了由层间电场反转、层间堆叠反转和两个量的同时反转形成的局域畴壁附近的边界模的不同电子性质。边界模式的性质与拓扑转变和间隙闭合有关，它们发生在体哈密顿参数空间中。谷间耦合效应没有直接捕获的连续模型所发挥的重要作用，解决使用晶格计算特定的畴壁结构。
Electronic states at domain walls in bilayer graphene are studied by analyzing their four- and two-band continuum models, by performing numerical calculations on the lattice, and by using quantum geometric arguments. The continuum theories explain the distinct electronic properties of boundary modes localized near domain walls formed by interlayer electric field reversal, by interlayer stacking reversal, and by simultaneous reversal of both quantities. Boundary mode properties are related to topological transitions and gap closures, which occur in the bulk Hamiltonian parameter space. The important role played by intervalley coupling effects not directly captured by the continuum model is addressed using lattice calculations for specific domain wall structures.