Superfluid phase stiffness in electron doped superconducting Gd-123

Abstract

Current–voltage characteristics of Ce substituted Gd-123 superconductor exhibits nonlinearity below a certain temperature below the critical temperature. An exponent is extracted using the nonlinearity of current–voltage relation. Superfluid phase stiffness has been studied as a function of temperature following the Ambegaokar–Halperin–Nelson–Siggia (AHNS) theory. Phase stiffness of the superfluid below the superconducting transition is found to be sensitive to the change in the carrier concentration in superconducting system. There may be a crucial electron density which affects superfluid stiffness strongly. Electron doping is found to be effective even if the coupling of the superconducting planes is changed.