Topological Kondo effect with Majorana fermions

TL;DR

This paper introduces a novel topological Kondo effect driven by Majorana fermions, leading to non-Fermi liquid behavior and unique transport signatures, with implications for topological quantum computing.

Contribution

It demonstrates how Majorana-induced topological degeneracy results in a new Kondo effect with distinctive non-Fermi liquid properties.

Findings

Predicts unique transport signatures of the topological Kondo effect

Shows robustness of non-Fermi liquid behavior in this context

Links Majorana fermions to potential topological quantum computation

Abstract

The Kondo effect is a striking consequence of the coupling of itinerant electrons to a quantum spin with degenerate energy levels. While degeneracies are commonly thought to arise from symmetries or fine-tuning of parameters, the recent emergence of Majorana fermions has brought to the fore an entirely different possibility: a "topological degeneracy" which arises from the nonlocal character of Majorana fermions. Here we show that nonlocal quantum spins formed from these degrees of freedom give rise to a novel "topological Kondo effect". This leads to a robust non-Fermi liquid behavior, known to be difficult to achieve in the conventional Kondo context. Focusing on mesoscopic superconductor devices, we predict several unique transport signatures of this Kondo effect, which would demonstrate the non-local quantum dynamics of Majorana fermions, and validate their potential for topological quantum computation.