In situ doping control of the surface of high-temperature superconductors

M.A. Hossain, J.D.F. Mottershead, D. Fournier, A. Bostwick, J.L. McChesney, E. Rotenberg, R. Liang, W.N. Hardy, G.A. Sawatzky, I.S. Elfimov, D.A. Bonn, A. Damascelli. Nat. Phys. 4, 527-531 (2008).