金属界面处的超快电子动力学：镜像态电子的带内弛豫作为摩擦

Ultrafast electron dynamics at metal interfaces: intraband relaxation of image state electrons as friction.

作者信息

Garrett-Roe Sean, Shipman Steven T, Szymanski Paul, Strader Matthew L, Yang Aram, Harris Charles B

机构信息

Chemistry Department, University of California-Berkeley, Berkeley, CA 94720, USA.

出版信息

J Phys Chem B. 2005 Nov 3;109(43):20370-8. doi: 10.1021/jp051977z.

DOI:10.1021/jp051977z

PMID:16853636

Abstract

Two-photon photoemission of image potential states above monolayers of p-xylene/Ag(111) shows that electrons with different momenta have very different rise and decay rates as a function of parallel momentum. The dynamics are due to energy and momentum loss (intraband relaxation), which we model as a stochastic process isomorphic to the overdamped motion of a harmonic oscillator. The method extracts a friction coefficient from the data which can be explained by electron-electron scattering in a formalism based on the Lindhard dielectric function. One-electron excitations (interband transistions) dominate the dissipation mechanism, with a smaller contribution from collective electronic excitations (plasmons).

摘要

对二甲苯/Ag(111)单分子层上方镜像势态的双光子光发射表明，具有不同动量的电子，其上升和衰减速率随平行动量的变化差异很大。这种动力学源于能量和动量损失（带内弛豫），我们将其建模为一个与简谐振荡器的过阻尼运动同构的随机过程。该方法从数据中提取出一个摩擦系数，这可以在基于林哈德介电函数的形式体系中通过电子-电子散射来解释。单电子激发（带间跃迁）主导耗散机制，集体电子激发（等离子体激元）的贡献较小。