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

Abstract

A topological superconducting wire with an effective time-reversal symmetry is known to have a Z8 topological classification in the presence of interactions. The topological index |n|≤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.