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A few theories of superconductivity describe, within a single framework, the coexistence of electron singlet and triplet pairing quantum states. Recently, a generalized Hubbard model including the first and second neighbor correlated-hopping interactions, in addition to the repulsive Coulomb ones, permit to explain the superconducting symmetries with spin triplet and singlet states, where the spatial symmetry of the Cooper pairs wave function have p- and d-wave, respectively [1]. Based on the BCS formalism, the correlated hopping interactions has been applied to a slightly distorted square lattice in order to obtain the superconducting state for p-wave gap D(k) =Dp [(sin(akx) ± isin(aky)], which satisfy the time reversal broken symmetry assumed in the Sr2RuO4 and other triplet superconductors. In order to compare the possible competition between the p- and d-wave symmetries at finite temperature, it has been analyzed the Helmholtz free energy and the critical temperature (Tc) as a function of electron density (n), likewise, the electronic specific heat in the superconducting state. A discussion for possible applications of these results to spintronic devices is offered.
References 1. J. Samuel Millán, Luis A. Pérez, Evgen Shelomov and Chumin Wang, Physica C 460-462 Part 2, 1051-1052 (2007). |
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