Condensed Matter Seminar Series
Brookhaven National Laboratory
Competing orders in graphene-based heterostructures
Motivated by graphene-based heterostructures like intercalated graphene and twisted bilayer graphene, I consider competing orders around Van Hove fillings in 2D hexagonal systems that arise due to amplified interactions from the increased density of states. This includes mechanisms for superconductivity from repulsive interactions, and in particular the possibility to obtain a topological d+id superconducting state. I discuss how the conventional Van Hove scenario qualitatively changes when accounting for the following effects in the different hexagonal heterostructures: a flattened dispersion along one direction at high-order Van Hove points, additional orbital or valley degrees of freedom, or incommensurate positions and non-local cluster interactions.