Kondo Effect Route to Probing Majorana-Kramers Pairs Coupled to Quantum Dot

TL;DR

This paper investigates how Majorana-Kramers pairs influence the Kondo effect in quantum dots, proposing dynamical spin susceptibility as an experimental signature for detecting Majorana fermions in topological superconductors.

Contribution

It presents the first renormalization group analysis of Majorana-Kramers pairs' signatures in quantum dot spin susceptibility, linking Majorana physics to Kondo phenomena.

Findings

Majorana-Kramers pairs affect the dynamical spin susceptibility of quantum dots.

Renormalization group flow equations reveal signatures of Majorana fermions.

Proposes dynamical spin susceptibility as an experimental probe for Majorana fermions.

Abstract

In this paper, we study a set-up in which quantum dot is tunnel-coupled to Majorana-Kramers pair(MKP) which are the edge modes of time reversal invariant topological superconductor (TRITOPS), which is an experimental realization of time reversal invariant Kitaev chain model. Our motivation is to study the effect of Majorana-Kramers pair on Kondo fixed point and conversely the effect of Kondo interaction on Majorana-Kramers pair. This way we can capture the signatures of Majorana fermions on Kondo effect in quantum dots which can be probed feasibly in experiments. Employing the renormalization group method, we report the first study of the signatures of Majorana-Kramers pair in the dynamical spin susceptibility of the quantum dot electrons. We not only calculate the flow equations for coupling constants but also study the renormalization of observables and especially calculate dynamical spin susceptibility. We propose that since these dynamical quantities have signatures of Majorana-Kramers pair, so they provide an unambiguous experimental probe for detection of Majorana fermions in TRITOPS.