Graphene Nanoribbons as a Majorana Platform

TL;DR

This paper explores how graphene nanoribbons coupled with Ising superconductors can host topologically nontrivial phases supporting Majorana zero modes, with potential applications in quantum computing.

Contribution

It introduces a model of a heterostructure combining ZGNRs and Ising superconductors to induce topological superconductivity and Majorana modes.

Findings

Induction of spin-triplet odd-parity pairing in ZGNRs

Topologically nontrivial superconducting phases identified

Gate-tunable transitions enable Majorana zero modes

Abstract

Graphene nanoribbons support a range of electronic phases that can be controlled via external stimuli. Zigzag-edged graphene nanoribbons (ZGNRs), in particular, exhibit an antiferromagnetic insulating ground state that transitions to a half-metallic phase under a transverse electric field or when embedded inside hexagonal Boron Nitride. Here, we consider a simple model of a heterostructure of a ZGNR with an Ising superconductor and show that, the Ising superconductor with a parent s-wave spin-singlet pairing can induce spin-triplet odd-parity pairing in the half-metallic phase of the ZGNR. The resulting superconducting phase is topologically nontrivial, with gate-tunable transitions that enable the emergence of Majorana zero modes.