Alternative paths to realize Majorana Fermions in Superconductor-Ferromagnet Heterostructures

TL;DR

This paper proposes a novel method to realize Majorana fermions in superconductor-ferromagnet heterostructures by using a quartet coupling rule, avoiding the need for exotic materials with strong spin-orbit coupling.

Contribution

It introduces an alternative approach to generate Majorana fermions through coexisting Zeeman fields and charge currents, expanding possibilities beyond traditional spin-triplet p-wave superconductor methods.

Findings

Demonstrates that Zeeman fields combined with charge currents can induce p-wave pairing.

Shows potential for engineering Majorana fermions in various heterostructures without exotic materials.

Suggests compatibility with recent experiments reporting Majorana fermions.

Abstract

A fundamental obstacle for achieving quantum computation is local decoherence. One way to circumvent this problem rests on the concepts of topological quantum computation using non-local information storage, for example on pairs of Majorana fermions (MFs). The arguably most promising way to generate MFs relies at present on spin-triplet p-wave states of superconductors (SC), which are not abundant in nature, unfortunately. Thus, proposals for their engineering in devices, usually via proximity effect from a conventional SC into materials with strong spinorbit coupling (SOC), are intensively investigated nowadays. Here we take an alternative path, exploiting the different connections between fields based on a quartet coupling rule for fields introduced by one of us, we demonstrate that, for instance, coexisting Zeeman field with a charge current would provide the conditions to induce p-wave pairing in the presence of singlet superconductivity. This opens new avenues for the engineering of robust MFs in various, not necessarily (quasi-)one-dimensional, superconductor-ferromagnet heterostructures, including such motivated by recent pioneering experiments that report MFs, in particular, without the need of any exotic materials with special structures of intrinsic SOC.