Petek Hrvoje, Ogawa Susumu
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Annu Rev Phys Chem. 2002;53:507-31. doi: 10.1146/annurev.physchem.53.090701.100226. Epub 2001 Oct 4.
This review presents a case study of the direct, real-time observation of a surface photochemical reaction, namely the frustrated photodesorption of alkali atoms from noble metal surfaces. Charge transfer excitation of an electron from the metal substrate into an unoccupied resonance of the alkali atom instantaneously turns on the repulsive Coulomb force inducing the nuclear motion of both the adsorbate and substrate atoms. The incipient nuclear wave packet dynamics are documented for the case of Cs/Cu(111) through the accompanying change in the surface electronic structure. The intimate view of atoms attempting to escape the surface bond highlights the unique role of the substrate in the electronic and nuclear dynamics that ultimately determine the product yields. Moreover, slow dephasing of the coherent polarization is exploited to demonstrate the control of nuclear wave packets through the phase of the excitation light.
本综述介绍了一个表面光化学反应直接实时观测的案例研究，即碱金属原子从贵金属表面的受挫光脱附。电子从金属基底转移激发到碱金属原子的未占据共振态，瞬间开启排斥性库仑力，引发吸附原子和基底原子的核运动。通过表面电子结构的伴随变化，记录了Cs/Cu(111)情况下初始核波包动力学。对试图逃离表面键的原子的近距离观察突出了基底在最终决定产物产率的电子和核动力学中的独特作用。此外，利用相干极化的缓慢退相来证明通过激发光的相位对核波包的控制。
