Majorana-Kondo competition in a cross-shaped double quantum dot-topological superconductor system

TL;DR

This paper investigates how Majorana quasiparticles influence the Kondo effect and transport properties in a double quantum dot system coupled to a topological superconductor, revealing modifications in Kondo temperatures and low-energy behavior.

Contribution

It provides a detailed analysis of the interplay between Majorana modes and Kondo correlations using numerical renormalization group methods, highlighting their impact on low-temperature transport.

Findings

Majorana quasiparticles affect both spin channels in transport.

Presence of Majoranas modifies Kondo temperature scales.

Low-energy transport behavior is significantly altered by Majorana coupling.

Abstract

We examine the transport properties of a double quantum dot system coupled to a topological superconducting nanowire hosting Majorana quasiparticles at its ends, with the central quantum dot attached to the left and right leads. We focus on the behavior of the local density of states and the linear conductance, calculated with the aid of the numerical renormalization group method, to describe the influence of the Majorana coupling on the low-temperature transport properties induced by the Kondo correlations. In particular, we show that the presence of Majorana quasiparticles in the system affects both the spin-up and spin-down transport channels, affecting the energy scales associated with the first-stage and second-stage Kondo temperatures, respectively, and modifying the low-energy behavior of the system.