Superfluid density near the critical temperature in the presence of random planar defects

摘要

The superfluid density near the superconducting transition is investigated inthe presence of spatial inhomogeneity in the critical temperature. Disorder isaccounted for by means of a random $T_c$ term in the conventionalGinzburg-Landau action for the superconducting order parameter. Focusing on thecase where a low-density of randomly distributed planar defects are responsiblefor the variation of $T_c$, we derive the lowest order correction to thesuperfluid density in powers of the defect concentration. The correction iscalculated assuming a broad Gaussian distribution for the strengths of thedefect potentials. Our results are in a qualitative agreement with thesuperfluid density measurements in the underdoped regime of high-quality YBCOcrystals by Broun and co-workers.