Direct Evidence of Two Superconducting Gaps in FeSe${}_{0.5}$Te${}_{0.5}$: SnS-Andreev Spectroscopy and Lower Critical Field

T. E. Kuzmicheva, S. A. Kuzmichev, A. V. Sadakov +7

We present direct measurements of the superconducting order parameter in nearly optimal FeSe${}_{0.5}$Te${}_{0.5}$ single crystals with critical temperature $T_C\approx 14$ K. Using i…