title: Communication: Momentum-resolved quantum interference in optically excited surface states.
abstract: Surface states play essential roles in condensed matter physics, e.g., as model two-dimensional (2D) electron gases and as the basis for topological insulators. Here, we demonstrate quantum interference in the optical excitation of 2D surface states using the model system of C(60)/Au(111). These surface states are transiently populated and probed in a femtosecond time- and angle-resolved two-photon photoemission experiment. We observe quantum interference within the excited populations of these surface states as a function of parallel momentum vector. Such quantum interference in momentum space may allow one to control 2D transport properties by optical fields.
authors.affiliation: Department of Chemistry & Biochemistry, University of Texas, Austin, Texas 78712, USA.
authors.forename: Wai-Lun
authors.initials: WL
authors.lastname: Chan
authors.forename: John
authors.initials: J
authors.lastname: Tritsch
authors.forename: Andrei
authors.initials: A
authors.lastname: Dolocan
authors.forename: Manuel
authors.initials: M
authors.lastname: Ligges
authors.forename: Luis
authors.initials: L
authors.lastname: Miaja-Avila
authors.forename: X-Y
authors.initials: XY
authors.lastname: Zhu