Isotropic three-dimensional gap in the iron arsenide superconductor LiFeAs from directional heat transport measurements
Isotropic three-dimensional gap in the iron arsenide superconductor LiFeAs from directional heat transport measurements
The thermal conductivity $\ensuremath{\kappa}$ of the iron-arsenide superconductor LiFeAs (${T}_{c}\ensuremath{\simeq}$ 18 K) was measured in single crystals at temperatures down to $T\ensuremath{\simeq}50$ mK and in magnetic fields up to $H=17$ T, very close to the upper critical field ${H}_{c2}\ensuremath{\simeq}18$ T. For both directions of the heat current, parallel and perpendicular …