title: One-dimensional plasmon in an atomic-scale metal wire.
abstract: We have measured one-dimensional (1D) plasmons in an atom wire array on the Si(557)-Au surface by inelastic scattering of a highly collimated slow electron beam. The angular dependence of the excitation energy clearly indicates the strong 1D confinement and free propagation of the plasma wave along the wire. The observed plasmon dispersion is explained very well by a quantum-mechanical scheme which takes into account dynamic exchange-correlation effects, interwire interactions, and spin-orbit splitting of the 1D bands. Although the qualitative feature of the plasmon dispersion is reminiscent of that of a high-density free-electron gas, we detected the substantial influence of electron correlation due to strong 1D confinement.
authors.affiliation: Nano System Functionality Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan. NAGAO.Tadaaki@nims.go.jp
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Nagao
authors.forename: Shin
authors.initials: S
authors.lastname: Yaginuma
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inaoka
authors.forename: Toshio
authors.initials: T
authors.lastname: Sakurai