Dynamics of clusters at surfaces

目标是对与表面接触的簇的动力学过程进行理论描述。我们的目标是开发一个最有效的描述团簇表面相互作用，以允许处理更大的团簇。我们将强调非线性体系中的电子动力学，并同时讨论离子动力学。预期的应用是：1)基材对动态过程的影响；2)簇状沉积动力学，跟踪电子发射以及电子进出衬底的转移；3)激光激发沉积团簇后的多光子发射，发射电子的角度和动能分布；4)沉积金属团簇中电子弛豫过程的泵-探针分析。研究沉积团簇的光学响应一直是探索适当调整动力学情景的第一步。这本身就是一项有趣的任务，特别是关于基质的影响。用于研究的工具是与经典离子分子动力学耦合的时变局部密度近似水平上的密度泛函方法。目前已经有一堆代码：一个完全成熟的三维TDLDA-MD代码，一个轴向二维的对称限制变体，以及半经典近似。

Goal is the theoretical description of dynamical processes of clusters in contact with surfaces. We aim at developing a most efficient description of the cluster-surface interaction to allow the treatment of larger clusters. We will emphasize electronic dynamics in the non-linear regime, augmented by a simultaneous treatment of ionic dynamics. Intended applications are: 1) influence of the substrate on the dynamical processes; 2) dynamics of cluster deposit, tracking electron emission as well as electron transfer into and from the substrate; 3) multi-photon emission following laser excitation of deposited clusters, angular and kinetic-energy distribution of emitted electrons; 4) pump-and-probe analysis of electronic relaxation processes in deposited metal clusters. Investigation of optical response of deposited clusters is always the first step to explore proper tuning of dynamical scenarios. And it is an interesting task of its own, particularly what the influence of the substrate is concerned. Tools for the investigations are density-functional methods at the level of the time-dependent local-density approximation coupled to classical ionic molecular dynamics. There exists already a pool of codes for that: a fully fledged three-dimensional TDLDA-MD code, a symmetry restricted variant thereof in axial two dimensions, and semi-classical approximations.