Superconducting gap with sign reversal between hole pockets in heavily hole-doped Ba1-xKxFe2As2

D. Watanabe, T. Yamashita, Y. Kawamoto +16

To gain insight into the unconventional superconductivity of Fe-pnictides with no electron pockets, we measure the thermal conductivity $\kappa$ and penetration depth $\lambda$ in the heavily…