Size Effects on Transport Properties in Topological Anderson Insulators

TL;DR

This paper investigates how the size of nanoribbons affects transport properties in topological Anderson insulators, revealing that narrower ribbons lose quantized conductance due to edge state coupling and increased backscattering.

Contribution

It provides a detailed analysis of size-dependent transport behavior in topological Anderson insulators using Green function methods, highlighting the loss of quantization in narrow ribbons.

Findings

Quantized conductance plateaus disappear in narrow nanoribbons.

Edge states on opposite sides can couple, increasing backscattering.

Main conductance contribution still comes from edge states.

Abstract

We study the size effects on the transport properties in topological Anderson insulators by means of the Landauer-B\"uttiker formalism combined with the nonequilibrium Green function method. Conductances calculated for serval different widths of the nanoribbons reveal that there is no longer quantized plateaus for narrow nanoribbons. The local spin-resolved current distribution demonstrates that the edge states on the two sides can be coupled, leading to enhancement of backscattering as the width of the nanoribbon decreases, thus destroying the perfect quantization phenomena in the topological Anderson insulator. We also show that the main contribution to the nonquantized conductance also comes from edge states. Experiment proposals on topological Anderson insulator are discussed finally.