Effect of Coulomb impurities on the electronic structure of magic angle twisted bilayer graphene

Journal article

Twisted van der Waals materials have risen as highly tunable platform 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 moire pattern. We demonstrate a variety of topological states with different Chern numbers highly tunable through doping, strain and bias voltage. Our proposal does not depend on a fine tuning of the twist angle, but solely on the emergence of moire minibands and is applicable for twist angles between 1.3 and 3 degrees. Our results establish the potential of twisted graphene bilayers to create artificial topological superconductivity without requiring ultraflat dispersions.Comment: 6 pages, 3 figure

Authors: Ramzan, MS; Goodwin, ZAH; Mostofi, AA; Kuc, A; Lischner, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: npj 2D Materials and Applications
• Volume: 7
• Issue: 1
• Pages: 49
• Publication date: 2023-07-10
• DOI: 10.1038/s41699-023-00403-2
• EISSN: 2397-7132
• ISSN: 2397-7132
• Language: English
• Keywords: Condensed matter physics; Materials science; Physics; Electron; Quantum mechanics; Scanning tunneling microscope; Nanotechnology; Bilayer graphene; Fermi energy; Graphene; Fermi level