Superconductivity dichotomy in K-coated single and double unit cell FeSe films on SrTiO3

Chenjia Tang, Ding Zhang, Yunyi Zang +12

We report the superconductivity evolution of one unit cell (1-UC) and 2-UC FeSe films on SrTiO3(001) substrates with potassium (K) adsorption. By in situ scanning tunneling spectro…