Transport signatures of interacting fermions in quasi-one-dimensional topological superconductors

TL;DR

This paper investigates how interactions in quasi-one-dimensional topological superconductors lead to Kondo-like states, affecting conductance and noise characteristics, with implications for understanding Majorana modes and topological classifications.

Contribution

It demonstrates the emergence of Kondo-like correlated states in interacting topological superconductors and analyzes their impact on transport properties and resonance splitting.

Findings

Kondo-like states induce anomalous conductance temperature dependence

Anomalous Fano factor observed in zero-temperature current

Splitting of Kondo resonance under symmetry-breaking perturbations

Abstract

A topological superconducting wire with an effective time reversal symmetry is known to have a $\mathbb{Z}_8$ topological classification in the presence of interactions. The topological index $|n| \le 4$ counts the number of Majorana end states, negative $n$ corresponding to end states that are odd under time reversal. If such a wire is weakly coupled to a normal-metal lead, interactions induce a Kondo-like correlated state if $|n| = 4$. We show that the Kondo-like state manifests itself in an anomalous temperature dependence of the zero-bias conductance and by an anomalous Fano factor for the zero-temperature normally-reflected current at finite bias. We also consider the splitting of the effective Kondo resonance for weak symmetry-breaking perturbations.