We study the low-energy electronic structure of heterostructures formed by one sheet of graphene placed on a monolayer of NbSe2. We build a continuous low-energy effective model that takes into account the presence of a twist angle between graphene and NbSe2, and of spin-orbit coupling and superconducting pairing in NbSe2. We obtain the parameters entering the continuous model via ab-initio calculations. We show that despite the large mismatch between the graphene's and NbSe2's lattice constants, due to the large size of the NbSe2's Fermi pockets, there is a large range of values of twist angles for which a superconducting pairing can be induced into the graphene layer. In addition, we show that the superconducting gap induced into the graphene is extremely robust to an external in-plane magnetic field. Our results show that the size of the induced superconducting gap, and its robustness against in-plane magnetic fields, can be significantly tuned by varying the twist angle.
@article{arxiv.1903.00475,
title = {Superconductivity in twisted Graphene ${\rm NbSe_2}$ heterostructures},
author = {Yohanes S. Gani and Hadar Steinberg and Enrico Rossi},
journal= {arXiv preprint arXiv:1903.00475},
year = {2019}
}