Strong pressure dependence of the magnetic penetration depth in single crystals of the heavy fermion superconductor CeCoIn5 studied by muon spin rotation

TL;DR

This study reveals that applying pressure to CeCoIn5 significantly reduces the magnetic penetration depth, indicating an increase in superconducting quasiparticles, while other anisotropic properties remain unchanged.

Contribution

It provides new insights into how pressure influences the superconducting properties and quasiparticle dynamics in CeCoIn5 through muon spin rotation measurements.

Findings

Strong decrease of  with pressure

Pressure independence of / and ^2(T)

Linear relationship between 1/^2 and Tc

Abstract

In the tetragonal heavy fermion system CeCoIn5 the unconventional superconducting state is probed by means of muon spin rotation. The pressure dependence (0-1 GPa) of the basal-plane magnetic penetration depth (\lambda_a), the penetration depth anisotropy (\gamma=\lambda_c/\lambda_a) and the temperature dependence of 1/\lambda_i^2 (i=a,c) were studied in single crystals. A strong decrease of \lambda_a with pressure was observed, while \gamma and \lambda_i^2(0)/\lambda_i^2(T) are pressure independent. A linear relationship between 1/\lambda_a^2(270 mK) and Tc was also found. The large decrease of \lambda_a with pressure is the signature of an increase of the number of superconducting quasiparticles by a factor of about 2.