Magnetic-field-dependent pinning potential in LiFeAs superconductor from its Campbell penetration depth
Magnetic-field-dependent pinning potential in LiFeAs superconductor from its Campbell penetration depth
A theoretical critical current density ${j}_{c}(T,H)$, as opposite to commonly measured relaxed persistent (Bean) current ${j}_{B}$, was extracted from the Campbell penetration depth ${\ensuremath{\lambda}}_{C}(T,H)$ measured in single crystals of LiFeAs. The effective pinning potential is slightly nonparabolic, which follows from the magnetic-field-dependent Labusch parameter $\ensuremath{\alpha}$. At the equilibrium (upon field …