The triplet superconductivity in square lattices and its optimal doping dependence

摘要

In this work, we study the p-wave superconductivity in a square lattice within a Hubbard model, in which a second-neighbour correlated hopping Delta t(3) is included. An infinitesimal distortion of the right angles in the square lattice is considered, which leads to second correlated hoppings Delta t(3)+/-delta(3) in the (x) over cap +/-(y) over cap directions, respectively. This study is carried out by means of the BCS formalism and we found a triplet superconducting ground state even though V=0. The optimal electron density for the critical temperature and the superconducting gap is analyzed as a function of the parameters of the model. Finally, the single-particle excitation gap is also calculated for different electron densities. (c) 2005 Elsevier Ltd. All rights reserved.