title: Many-body interactions in quasi-freestanding graphene.
abstract: The Landau-Fermi liquid picture for quasiparticles assumes that charge carriers are dressed by many-body interactions, forming one of the fundamental theories of solids. Whether this picture still holds for a semimetal such as graphene at the neutrality point, i.e., when the chemical potential coincides with the Dirac point energy, is one of the long-standing puzzles in this field. Here we present such a study in quasi-freestanding graphene by using high-resolution angle-resolved photoemission spectroscopy. We see the electron-electron and electron-phonon interactions go through substantial changes when the semimetallic regime is approached, including renormalizations due to strong electron-electron interactions with similarities to marginal Fermi liquid behavior. These findings set a new benchmark in our understanding of many-body physics in graphene and a variety of novel materials with Dirac fermions.
authors.affiliation: Department of Physics, University of California, Berkeley, CA 94720, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Siegel
authors.forename: Cheol-Hwan
authors.initials: CH
authors.lastname: Park
authors.forename: Choongyu
authors.initials: C
authors.lastname: Hwang
authors.forename: Jack
authors.initials: J
authors.lastname: Deslippe
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Fedorov
authors.forename: Steven G
authors.initials: SG
authors.lastname: Louie
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lanzara