Delocalization of boundary states in disordered topological insulators

作者：Essin Andrew M^*; Gurarie Victor

来源：Journal of Physics A-Mathematical and Theoretical, 2015, 48(11): 11FT01.

DOI：10.1088/1751-8113/48/11/11FT01

• topological insulators
• quenched disorder
• Anderson localization

We use the method of bulk-boundary correspondence of topological invariants to show that disordered topological insulators have at least one delocalized state at their boundary at zero energy. Those insulators which do not have chiral (sublattice) symmetry have in addition the whole band of delocalized states at their boundary, with the zero energy state lying in the middle of the band. This result was previously conjectured based on the anticipated properties of the supersymmetric (or replicated) sigma models with WZW-type terms, as well as verified in some cases using numerical simulations and a variety of other arguments. Here we derive this result generally, in arbitrary number of dimensions, and without relying on the description in the language of sigma models.

• 出版日期2015-3-20