Meissner-like effect and conductivity of power-Maxwell holographic superconductors

Abstract

The full description of a superconductor requires that it has an infinite DC conductivity (or zero electrical resistivity) as well as expels the external magnetic fields. Thus, for any holographic superconductor which is dual to a real superconductor, it is necessary to examine, simultaneously, these two features based on the gauge/gravity duality. In this paper, we explore numerically these two aspects of the higher dimensional holographic superconductors, in the presence of a Power-Maxwell electrodynamics as the gauge field. At first, we calculate the critical temperature, condensation, conductivity, and superconducting gap, in the absence of magnetic field and disclose the effects of both power parameter, $s$, as well as the spacetime dimensions, $d$, on this quantities. Then, we immerse the superconductor into an external magnetic field, $B$, and observe that with increasing the magnetic field, the starting point of condensation occurs at temperature less than the critical temperature, $T_{c}$, in the absence of magnetic field. This implies that at a fixed temperature, we can define a critical magnetic field, above which the critical temperature goes to zero which is similar to the Meissner effect in superconductor. In these indications, we also try to show the distinction of the conformal invariance of the Power-Maxwell Lagrangian that occurs for $s=d/4$.