Zero-field superfluid density in a d-wave superconductor evaluated from muon-spin-rotation experiments in the vortex state

Abstract

We present an approach that allows the reconstruction of the zero-field magnetic penetration depth λ0 based on the results of muon-spin-rotation (μSR) experiments conducted in a superconductor in the vortex state. It was successfully applied to describe the μSR experiments in optimally doped (BiPb)2(SrLa)2CuO6+δ (OP Bi2201). We found that in unconventional d-wave superconductors (such as OP Bi2201) only at relatively low magnetic fields [B/Bc2≲10−3; Bc2 is the upper critical field] the effective penetration depth λeff, obtained in μSR experiment, is a good measure of λ0. The high-field data need to be evaluated accounting for both the nonlinear and the nonlocal corrections.