Signature of multigap nodeless superconductivity in fluorine-doped NdFeAsO
Signature of multigap nodeless superconductivity in fluorine-doped NdFeAsO
We investigate the temperature dependence of the lower critical field ${H}_{c1}(T)$, the field at which vortices penetrate into the sample, of a high-quality fluorine-doped NdFeAsO single crystal under static magnetic fields $H$ parallel to the $c$ axis. The temperature dependence of the first vortex penetration field has been experimentally obtained …