1202.3375 (J. Vucicevic et al.)

Theoretical study of d-wave superconductivity in doped bilayer graphene    [PDF]

J. Vucicevic, D. Tanaskovic, M. O. Goerbig, M. V. Milovanovic

We introduce a microscopic model on the honeycomb bilayer, which in the
small-momentum limit captures the usual description of bilayer graphene. Due to
assumed strong interlayer hopping it reduces to an effective honeycomb
monolayer model with also third neighbor hopping. We study interaction effects
in this effective model focusing on possible superconducting instabilities. We
find $d_{x^2-y^2}$ superconductivity in the strong coupling limit of an
effective $tJ$-model-like description that gradually transforms into $d + i d$
time reversal symmetry breaking superconductivity at weak couplings. In this
limit the small momentum order parameter expansion is $(k_x + i k_y)^2$ (or
$(k_x - i k_y)^2$) at both points (valleys) of effective, low-energy
description. The relevance of our model and investigation for the physics of
bilayer graphene is also discussed.

View original: http://arxiv.org/abs/1202.3375