Transport properties of topological superconductor-Luttinger liquid junctions: a real-time Keldysh approach

TL;DR

This paper develops a real-time Keldysh framework to analyze the transport properties of topological superconductor-Luttinger liquid junctions, revealing how interactions influence zero-bias conductance quantization related to Majorana modes.

Contribution

The paper introduces a novel real-time Keldysh approach to compute tunneling conductance in interacting nanowire-superconductor junctions, incorporating finite temperature and voltage effects.

Findings

Quantization of zero-bias conductance at zero temperature due to Majorana modes

Interactions can significantly alter tunneling conductance predictions

Framework applicable to realistic experimental conditions

Abstract

Inspired by a recent experimental observation of the zero-bias tunneling conductance in superconductor-semiconductor nanowire devices, we consider here transport properties of the junctions consisting of a nanowire (Luttinger liquid) coupled to a topological superconductor characterized by the presence of Majorana zero-energy end states. The presence of the Majorana modes leads to a quantization of the zero-bias tunneling conductance at zero temperature. In order to understand this phenomenon, we have developed a framework, based on real-time Keldysh technique, which allows one to compute tunneling conductance at finite temperature and voltage in a realistic experimental setup. Our approach allows one to understand this transport phenomenon from a more general perspective by including the effect of interactions in the nanowire, which sometimes results in a drastic departure from the non-interacting predictions. Thus, our results provide a key insight for the tunneling experiments aiming at detecting Majorana particles in one-dimensional nanowire devices.