Impurity effect on surface states of Bi (111) ultrathin films

Zhu Kai^{1, 2}, Tian Dai^{1, 2}, Wu Lin^{1, 2}, Xu Jianli^{1, 2}, Jin Xiaofeng^{1, 2, †,}

Representative RHEED pattern of the Si (111)-7×7 surface (a) and a 5.0-nm Bi (111) films (b). The temperature dependence of the square resistivity ρ_xx of a 5.0-nm pristine Bi (111) film and with 0.5-ML Cu, Fe, and Co impurities on top is shown in panels (c), (d), and (e), respectively.