Probing Majorana Physics in Quantum Dot Shot Noise Experiments

TL;DR

This paper investigates how shot noise measurements in a quantum dot coupled to a topological superconductor can differentiate Majorana zero modes from other phenomena like Kondo effects, providing a new diagnostic tool.

Contribution

It introduces a method to distinguish Majorana zero modes from Kondo physics using shot noise analysis in quantum dot experiments.

Findings

Shot noise exhibits distinct signatures for Majorana zero modes.

Tunneling conductance alone cannot reliably differentiate Majorana from Kondo effects.

The combined analysis of conductance and shot noise enhances identification of topological states.

Abstract

We consider a quantum dot coupled to a topological superconductor and two normal leads and study transport properties of the system. Using Keldysh path-integral approach, we study current fluctuations (shot noise) within the low-energy effective theory. We argue that the combination of the tunneling conductance and the shot noise through a quantum dot allows one to distinguish between the topological (Majorana) and non-topological (e.g., Kondo) origin of the zero-bias conduction peak. Specifically, we show that, while the tunneling conductance might exhibit zero-bias anomaly due to Majorana or Kondo physics, the shot noise is qualitatively different in the presence of Majorana zero modes.