1202.0651 (J. P. F. LeBlanc et al.)

Distinguishing Coulomb and electron-phonon interactions for massless
Dirac fermions    [PDF]

J. P. F. LeBlanc, Jungseek Hwang, J. P. Carbotte

While many physical properties of graphene can be understood qualitatively on
the basis of bare Dirac bands, there is specific evidence that
electron-electron (EE) and electron-phonon (EP) interactions can also play an
important role. We discuss strategies for extracting separate images of the EE
and EP interactions as they present themselves in the electron spectral density
and related self-energies. While for momentum, $k$, equal to its Fermi value,
$k_F$, a composite structure is obtained which can be difficult to separate
into its two constituent parts, at smaller values of $k$ the spectral function
shows distinct incoherent sidebands on the left and right of the main
quasiparticle line. These image respectively the EE and EP interactions, each
being most prominent in its own energy window. We employ a maximum entropy
inversion technique on the self energy to reveal the electron-phonon spectral
density separate from the excitation spectrum due to coulomb correlations. Our
calculations show that this technique can provide important new insights into
inelastic scattering processes in graphene.

View original: http://arxiv.org/abs/1202.0651