2011/03/31 by J. Gonzalez, J. González · 1 citation
Engineering · Materials Science · Mathematics · Physics and Astronomy · #Chiral symmetry breaking #Condensed matter physics #Electron and X-Ray Spectroscopy Techniques #Geometry #Graphene #Graphene research and applications #Materials science #Mathematics #Nanopore and Nanochannel Transport Studies #Physics #Quantum mechanics #Symmetry (geometry) #Symmetry breaking #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.85.085420
4 pages, 2 figures, more references added
arxiv created 2011/04/11 · openalex publication_date 2012/02/13 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/23
We investigate the dynamical breakdown of the chiral symmetry in the theory of Dirac fermions in graphene with long-range Coulomb interaction. We analyze the electron-hole vertex relevant for the dynamical gap generation in the ladder approximation, showing that it blows up at a critical value \ensuremathαc in the graphene fine structure constant, which is quite sensitive to many-body corrections. Under static random phase approximation (RPA) screening of the interaction potential, we find that taking into account electron self-energy corrections to the vertex increases the critical coupling to \ensuremathαc\ensuremath≈4.9, for a number N=4 of two-component Dirac fermions. When dynamical screening of the interaction is instead considered, the effect of Fermi velocity renormalization in the electron and hole states leads to the value \ensuremathαc\ensuremath≈1.75 for N=4, substantially larger than that obtained without electron self-energy corrections (\ensuremath≈0.99), but still below the nominal value of the interaction coupling in isolated free-standing graphene.