Two healing lengths in a two-band GL-model with quadratic terms: Numerical results
Abstract
A two-band and quartic interaction order Ginzburg–Landau model in the presence of a single vortex is studied in this work. Interactions of second (quadratic, with coupling parameter ) and fourth (quartic, with coupling parameter ) order between the two superconducting order parameters ( with i = 1,2) are incorporated in a functional. Terms beyond quadratic gradient contributions are neglected in the corresponding minimized free energy. The solution of the system of coupled equations is solved by numerical methods to obtain the -profiles, where our starting point was the calculation of the superconducting critical temperature . With this at hand, we evaluate and the magnetic field along the z-axis, , as function of , , the radial distance and the temperature , for . The self-consistent equations allow us to compute (penetration depth) and the healing lengths of ( with i = 1,2) as functions of T, and . At the end, relevant discussions about type-1.5 superconductivity in the compounds we have studied are presented.