Abstract
Recent experiments on bi- and trilayer graphene have been interpreted as indications for interaction-induced gap openings in the electronic spectrum. We have performed extensive functional renormalization group studies of the low-energy effective interactions of electron in mono-, bi- and trilayer honeycomb lattices for a wider range of interaction parameters. Here we describe our theoretical expectations regarding the nature of the interacting ground states and the energy scales of possible gap openings. We also compare with model parameters given by ab-initio approaches and with Quantum Montecarlo calculations for onsite interactions. A major candidate for the ordered ground state is the antiferromagnetic spin-density wave, but also an interaction-induced quantum-spin-Hall state seem nearby.
Coffee and tea will be served 20 minutes prior to the seminar.