"Effects of disorder and dimerization on the surface states of weak 3D topological insulators" Hideaki Obuse
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Date
Location
Description
Effects of disorder and dimerization on the surface states of weak 3D topological insulators
Prof. Hideaki Obuse
Hokkaido University, Japan
- Date: Wednesday, 29 October
- Time: 14:00-15:00
- Venue: Meeting Room C015, Lab1
Abstract:
The topological insulators(TI) are classified into strong and weak TIs. The weak three-dimensional (3D) topological insulator is realized by stacking the strong two-dimensional(2D) topological insulators, that is, quantum spin Hall insulators. Recently, it has been identified experimentally that Bi14Rh3I9 is such a material. In this work, we study effects of disorder and dimerization of interlayer couplings on the 2D surface states of weak 3D topological insulators by constructing an effective model, called, spin-directed Z_2 network model. It is found that, without dimerization, the network model has no insulating phase for any disorder strength. However, a sufficiently strong dimerization induces a transition from a metallic phase to an insulating phase. The critical exponent for the diverging localization length at metal-insulator transition points is obtained by finite-size scaling analysis of numerical data from simulations of this network model. It is shown that the phase transition belongs to the two-dimensional symplectic universality class of the Anderson transition.
Reference: H. Obuse, S. Ryu, A. Furusaki, and C. Mudry, PRB 89, 155315 (2014)
Looking forward to seeing many of you.
Quantum Systems Unit
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