Direct evidence of superconductivity and determination of the superfluid density in buried ultrathin FeSe grown on SrTiO${}_3$

P. K. Biswas, Z. Salman, Q. Song +6

Bulk FeSe is superconducting with a critical temperature $T_c$ $\cong$ 8 K and SrTiO${}_3$ is insulating in nature, yet high-temperature superconductivity has been reported at the in…