Rüegg Andreas, Lin Chungwei
Department of Physics, University of California, Berkeley, California 94720, USA.
Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA.
Phys Rev Lett. 2013 Jan 25;110(4):046401. doi: 10.1103/PhysRevLett.110.046401. Epub 2013 Jan 22.
We investigate the electronic structure induced by wedge disclinations (conical singularities) in a honeycomb lattice model realizing Chern numbers γ = ± 1. We establish a correspondence between the bound state of (i) an isolated Φ(0)/2 flux, (ii) an isolated pentagon (n = 1) or heptagon (n = -1) defect with an external flux of magnitude nγΦ(0)/4 through the center, and (iii) an isolated square or octagon defect without external flux, where Φ(0) = h/e is the flux quantum. Because of the above correspondence, the existence of isolated electronic states bound to disclinations is robust against various perturbations. Hence, measuring these defect states offers an interesting probe of graphene-based topological insulators which is complementary to measurements of the quantized edge currents.
我们研究了在实现陈数γ = ±1的蜂窝晶格模型中，由楔形位错（锥形奇点）诱导的电子结构。我们建立了以下三者之间的对应关系：（i）一个孤立的Φ(0)/2磁通的束缚态；（ii）一个中心有大小为nγΦ(0)/4的外部磁通的孤立五边形（n = 1）或七边形（n = -1）缺陷；（iii）一个没有外部磁通的孤立正方形或八边形缺陷，其中Φ(0) = h/e是磁通量子。由于上述对应关系，与位错相关的孤立电子态的存在对于各种微扰具有鲁棒性。因此，测量这些缺陷态为基于石墨烯的拓扑绝缘体提供了一种有趣的探测手段，它与对量子化边缘电流的测量互为补充。
