Tolerance and breakdown of topological protection in a disordered waveguide

Author:

Kiyanoush Goudarzi, Moonjoo Lee

Keyword:

Condensed Matter, Disordered Systems and Neural Networks, Disordered Systems and Neural Networks (cond-mat.dis-nn), Optics (physics.optics), Quantum Physics (quant-ph)

journal:

date:

2023-09-13 16:00:00

Abstract

We consider a disordered waveguide consisting of trivial dielectric and non-trivial magnetically anisotropic material. A topologically-protected edge mode appears owing to the broken time-reversal symmetry of the non-trivial lattice. While the edge mode maintains under other position and radius disorders, the protection is immediately broken by applying a radius disorder to the non-trivial lattice. This breakdown originates from donor and acceptor modes occupying the topological bandgap. Furthermore, via the calculation of the Bott index, we show that Anderson localization occurs as a metal conducting gap changes to a topological gap along with increasing disorders.

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