Eur. Phys. J. B (2015) 88: 49
https://doi.org/10.1140/epjb/e2015-50727-0

Regular Article

Spin-dependent polaron formation in pristine graphene

¹ Department of Physics, Faculty of Sciences, Ankara University, 06100 Tandoğan, Ankara, Turkey
² Department of Physics, Ferdowsi University of Mashhad, Mashhad, Iran

^a e-mail: mogulkoc@science.ankara.edu.tr

Received: 17 October 2014
Received in final form: 16 January 2015
Published online: 18 February 2015

Abstract

We investigate the effects of spin-orbit couplings on the electron (hole)-E_2g phonon interaction in graphene. We examine the effects of spin-orbit couplings on electron and hole polaron formation as well as DC conductivity, and spin polarizations of charge carriers. We use Fröhlich type Hamiltonian to describe the electron-phonon system within the continuum limit. Our theoretical analysis shows that, the polaronic effect is decreased due to the spin-orbit couplings, for both spin and pseudospin states, but it is enhanced beyond some critical values of wavevector for spin-up states of both sublattices in the presence of spin-orbit couplings. The Rashba spin-orbit coupling in the graphene single layer splits up- and down- states, and produces perfect spin polarized conductivity. Also the phonon-restricted and phonon-assisted conduction are reported for positive and negative Fermi energies.