Kondo effect in a quantum dot embedded between topological superconductors

TL;DR

This paper investigates how Majorana zero modes influence the Kondo effect in a quantum dot system, revealing modifications in the density of states and conductance that could inform future quantum computing applications.

Contribution

It introduces a theoretical model combining Kondo physics with Majorana modes and analyzes their interplay using non-equilibrium Green's functions, highlighting novel anti-resonance phenomena.

Findings

Majorana modes induce anti-resonance in the Kondo density of states

The presence of Majorana modes leads to spin-resolved conductance features

Kondo resonance is significantly modified by Majorana zero modes

Abstract

In this article, we study the quantum transport through a single-level quantum-dot in Kondo regime, coupled to current leads and embedded between two one-dimensional topological superconductors, each hosting Majorana zero modes at their ends. The Kondo effect in the quantum dot is modeled by mean-field finite-$U$ auxiliary bosons approximation and solved by using the non-equilibrium Green's function approach. First, we calculate the density of states of the quantum dot, and then both the current and the differential conductance through the quantum dot in order to characterize the interplay between the Kondo resonance and Majorana zero modes. The results reveal that the presence of Majorana zero modes modifies the Kondo resonance exhibiting an anti-resonance structure in the density of states, leading to obtain spin-resolved behavior of the measurable current and differential conductance. We believe our findings could be helpful to understand the behavior of the Kondo effect in connection with Majorana zero modes.