Core-level spectra from bilayer graphene

We derive core-level spectra for doped free-standing bilayer graphene. Numerical results are presented for all nine combinations of the doping concentrations 10(12) cm(-2), 10(13) cm(-2), and 10(14) cm(-2 )in the two graphene sheets and we compare the results to the reference spectra for monolayer graphene. We furthermore discuss the spectrum of single-particle inter-band and intra-band excitations in the omega q-plane, and show how the dispersion curves of the collective modes are modified in the bilayer system. (C) 2016 Elsevier B.V. All rights reserved.