title: Unconventional superconductivity in generalized Hubbard model: role of electron-hole symmetry breaking terms.
abstract: We investigate the effect of the electron-hole (e-h) symmetry breaking on d-wave superconductivity induced by non-local effects of correlations in the generalized Hubbard model. The symmetry breaking is introduced in a two-fold manner: by the next-to-nearest neighbor hopping of electrons and by the charge-bond interaction-the off-diagonal term of the Coulomb potential. Both terms lead to a pronounced asymmetry of the superconducting order parameter. The next-to-nearest neighbor hopping enhances superconductivity for h-doping, while diminishes it for e-doping. The charge-bond interaction alone leads to the opposite effect and, additionally, to the kinetic-energy gain upon condensation in the underdoped regime. With both terms included, with similar amplitudes, the height of the superconducting dome and the critical doping remain in favor of h-doping. The influence of the charge-bond interaction on deviations from [Formula: see text] symmetry of the shape of the gap at the Fermi surface in the momentum space is briefly discussed.
authors.affiliation: International School for Advanced Studies (SISSA), via Bonomea 265, IT-34136, Trieste, Italy. Marian Smoluchowski Institute of Physics, Jagiellonian University, ul. Łojasiewicza 11, PL-30-348 Kraków, Poland.
authors.forename: Marcin M
authors.initials: MM
authors.lastname: Wysokiński
authors.forename: Jan
authors.initials: J
authors.lastname: Kaczmarczyk