2009/06/13 by Oskar Vafek, Kun Yang · 2 citations
Materials Science · Physics and Astronomy · #Graphene research and applications #Quantum Electrodynamics and Casimir Effect #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.81.041401
published as Phys. Rev. B 81, 041401(R) (2010) · 4 pages + references
arxiv created 2009/06/13 · openalex publication_date 2010/01/04 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Low-energy electronic structure of (unbiased and undoped) bilayer graphene consists of two Fermi points with quadratic dispersions if trigonal warping is ignored. We show that short-range (or screened Coulomb) interactions are marginally relevant and use renormalization group to study their effects on low-energy properties of the system. We find that the two quadratic Fermi points spontaneously split into four Dirac points. This results in a nematic state that spontaneously breaks the sixfold lattice rotation symmetry (combined with layer permutation) down to a twofold one, with a finite transition temperature. Critical properties of the transition and effects of trigonal warping are also discussed.