Spontaneous symmetry breaking and Lifshitz transition in bilayer graphene

TL;DR

This paper derives renormalization group equations for bilayer graphene, predicting a first-order phase transition involving symmetry breaking and a Lifshitz transition in the electron spectrum.

Contribution

It provides a theoretical framework for understanding phase transitions and topological changes in bilayer graphene due to short-range and Coulomb interactions.

Findings

Prediction of a first-order phase transition to a uniaxially deformed gapless state

Identification of a Lifshitz transition involving topology change of the electron spectrum

Derivation of RG equations for all symmetry-allowed interactions in bilayer graphene

Abstract

We derive the renormalization group equations describing all the short-range interactions in bilayer graphene allowed by symmetry and the long range Coulomb interaction. For certain range of parameters, we predict the first order phase transition to the uniaxially deformed gapless state accompanied by the change of the topology of the electron spectrum.