Eur. Phys. J. B (2014) 87: 187
https://doi.org/10.1140/epjb/e2014-50414-8

Regular Article

Scattering theory and ground-state energy of Dirac fermions in graphene with two Coulomb impurities

¹ Institut für Theoretische Physik, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
² Department of Mathematics, City University London, London EC1V 0HB, UK
³ Turin Polytechnic University in Tashkent, 17 Niyazov Street, 100095 Tashkent, Uzbekistan

^a e-mail: egger@thphy.uni-duesseldorf.de

Received: 19 June 2014
Published online: 11 August 2014

Abstract

We study the physics of Dirac fermions in a gapped graphene monolayer containing two Coulomb impurities. For the case of equal impurity charges, we discuss the ground-state energy using the linear combination of atomic orbitals (LCAO) approach. For opposite charges of the Coulomb centers, an electric dipole potential results at large distances. We provide a nonperturbative analysis of the corresponding low-energy scattering problem.