Interfacial Magnon-Mediated Superconductivity in Twisted Bilayer Graphene

TL;DR

This paper proposes a novel method to induce and control superconductivity in twisted bilayer graphene using magnon interactions mediated by ferromagnetic insulators, revealing tunable p-wave superconducting states.

Contribution

It introduces a new approach to achieve and tune magnon-mediated superconductivity in twisted bilayer graphene with ferromagnetic insulators, especially CrI3, enabling exponential control over the superconducting state.

Findings

Magnons can mediate interlayer superconductivity in twisted bilayer graphene.

CrI3 allows exponential tuning of the superconducting state via compression.

The induced superconductivity exhibits p-wave symmetry.

Abstract

The interfacial coupling between electrons and magnons in adjacent layers can mediate an attractive electron-electron interaction and induce superconductivity. We consider magic-angle twisted bilayer graphene sandwiched between two ferromagnetic insulators to optimize this effect. As a result, magnons induce an interlayer superconducting state characterized by $p$-wave symmetry. We investigate two candidate ferromagnets. The van der Waals ferromagnet CrI$_3$ stands out because it allows compression to tune the superconducting state with an exponential sensitivity. This control adds a new dimension to the tunability of twisted bilayer graphene. Our results open a new path for exploring magnon-induced superconductivity.