Hallmarks of Majorana mode leaking into a hybrid double quantum dot

TL;DR

This paper studies how Majorana zero modes influence the spectral and transport properties of a double quantum dot system, combining analytical and numerical methods to explore potential experimental signatures.

Contribution

It provides analytical expressions for bound states and investigates the interplay between Majorana modes and Kondo states using numerical renormalization group calculations.

Findings

Majorana modes leak into the quantum dots affecting spectral features

Kondo states coexist and interact with Majorana modes

Proposes experimental detection via Andreev spectroscopy

Abstract

We investigate the spectral and transport properties of a double quantum dot laterally attached to a topological superconducting nanowire, hosting the Majorana zero-energy modes. Specifically, we consider a geometry, in which the outer quantum dot is embedded between the external normal and superconducting leads, forming a circuit. First, we derive analytical expressions for the bound states in the case of an uncorrelated system and discuss their signatures in the tunneling spectroscopy. Then, we explore the case of strongly correlated quantum dots by performing the numerical renormalization group calculations, focusing on the interplay and relationship between the leaking Majorana mode and the Kondo states on both quantum dots. Finally, we discuss feasible means to experimentally probe the in-gap quasiparticles by using the Andreev spectroscopy based on the particle-to-hole scattering mechanism.