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Title: Kohn-Luttinger superconductivity in monolayer and bilayer semimetals with the Dirac spectrum

The effect of Coulomb interaction in an ensemble of Dirac fermions on the formation of superconducting pairing in monolayer and bilayer doped graphene is studied using the Kohn-Luttinger mechanism disregarding the Van der Waals potential of the substrate and impurities. The electronic structure of graphene is described using the Shubin-Vonsovsky model taking into account the intratomic, interatomic, and interlayer (in the case of bilayer graphene) Coulomb interactions between electrons. The Cooper instability is determined by solving the Bethe-Saltpeter integral equation. The renormalized scattering amplitude is obtained with allowance for the Kohn-Luttinger polarization contributions up to the second order of perturbation theory in the Coulomb interaction. It plays the role of effective interaction in the Bethe-Salpeter integral equation. It is shown that the allowance for the Kohn-Luttinger renormalizations as well as intersite Coulomb interaction noticeably affects the competition between the superconducting phases with the f-wave and d + id-wave symmetries of the order parameter. It is demonstrated that the superconducting transition temperature for an idealized graphene bilayer with significant interlayer Coulomb interaction between electrons is noticeably higher than in the monolayer case.
Authors:
 [1] ; ;  [2]
  1. Russian Academy of Sciences, Kapitza Institute for Physical Problems (Russian Federation)
  2. Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation)
Publication Date:
OSTI Identifier:
22472470
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 119; Journal Issue: 6; Other Information: Copyright (c) 2014 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BETHE-SALPETER EQUATION; DOPED MATERIALS; ELECTRONIC STRUCTURE; ELECTRONS; F WAVES; GRAPHENE; INTEGRAL EQUATIONS; LAYERS; ORDER PARAMETERS; POLARIZATION; POTENTIALS; RENORMALIZATION; SCATTERING AMPLITUDES; SEMIMETALS; SUBSTRATES; SUPERCONDUCTIVITY; TRANSITION TEMPERATURE; VAN DER WAALS FORCES