Abstract

MILLAN, B.; HERNANDEZ-HERNANDEZ, I. J.; PEREZ, L. A.  and  MILLAN, J. Samuel. Optimal electronic doping in p-wave superconductors. Rev. mex. fis. [online]. 2021, vol.67, n.6, 061601.  Epub Mar 14, 2022. ISSN 0035-001X.  https://doi.org/10.31349/revmexfis.67.061601.

Recently, within a generalized Hubbard model which includes correlated nearest (Δt) and next-nearest hopping interactions (Δt3), a comparative study between d- and s*- wave superconducting ground states on a square lattice was performed. It was found that the critical temperature of transition T c (n), as a function of the electron concentration n, reaches a maximum (T c-max ) at a given optimal doping (n op ) for each value of the ratio t´/t, where t and t´ are the tight-binding nearest and next-nearest hopping parameter of a square lattice, respectively. From all values obtained for $T_{c-\mathrm{m}\mathrm{a}\mathrm{x}}(t\text{'}/t,n_{op})$ a global minimum one was encountered for both symmetries. Likewise, in the same space, a minimal ground state energy Eg was also obtained. For d-wave channel both minima are localized around the same optimal doping. However, for s* symmetry, the two minima are located at different electron concentrations. In this work, we additionally study how the p-wave ground-state energy and the critical temperature depend on the hoppings parameters and the electron concentration. The results show that for p-wave, minimum global values of T c-max and Eg in the $(t\text{'}/t,n_{op})$ space do exist too, and are found around half filling but, as occurs for s *- wave, the minimum of T c-max does not occur at the same point as Eg. Moreover, we present a ground-state phase diagram in the space $(t\text{'}/t,n_{op})$ where it is possible to find zones of coexistence and competition between the s*-, p- and d-wave symmetries. Also, an analysis of the shape of the Fermi surface and the single-particle energy, as functions of the wave vector of an electron in the Cooper pair, has been done for different regions of the mentioned space.

Keywords : Theories and models of superconducting state; pairing symmetries (other than s-wave); pseudogap regime..