Detection of topological transitions by transport through molecules and nanodevices

TL;DR

This paper investigates how transport measurements, specifically zero-bias conductance, can detect topological phase transitions in molecular and nanodevices by analyzing effective impurity models and conductance peak behaviors.

Contribution

It introduces a method to identify topological charge transitions in interacting electronic systems through conductance analysis using impurity models.

Findings

Conductance peaks reveal topological phase transitions.

Effective impurity models accurately describe the system.

Flux and gate voltage variations can detect topological changes.

Abstract

We analyze the phase transitions of an interacting electronic system weakly coupled to free-electron leads by considering its zero-bias conductance. This is expressed in terms of two effective impurity models for the cases with and without spin degeneracy. We demonstrate using the half-filled ionic Hubbard ring that the weight of the first conductance peak as a function of external flux or of the difference in gate voltages between even and odd sites allows one to identify the topological charge transition between a correlated insulator and a band insulator.