Moiré-enabled topological superconductivity in twisted bilayer graphene

• Published in: 2d materials Vol. 11; no. 3; pp. 35012 - 35019
• Main Authors: Khosravian, Maryam, Bascones, Elena, Lado, Jose L
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.07.2024
• Subjects: topological superconductivity; twisted bilayer graphene; van der Waals heterostructures
• ISSN: 2053-1583; 2053-1583
• DOI: 10.1088/2053-1583/ad3b0c

Twisted van der Waals materials have risen as highly tunable platforms for realizing unconventional superconductivity. Here we demonstrate how a topological superconducting state can be driven in a twisted graphene multilayer at a twist angle of approximately 1.6 degrees proximitized to other 2D materials. We show that an encapsulated twisted bilayer subject to induced Rashba spin–orbit coupling, s-wave superconductivity, and exchange field generates a topological superconducting state enabled by the moiré pattern. We demonstrate the emergence of a variety of topological states with different Chern numbers, that are highly tunable through doping, strain, and bias voltage. Our proposal does not depend on fine-tuning the twist angle, but solely on the emergence of moiré minibands and is applicable for twist angles between 1.3 and 3 degrees. Our results establish the potential of twisted graphene bilayers to create topological superconductivity without requiring ultraflat dispersions.