Dissipative dynamics within the electronic friction approach: the femtosecond laser desorption of H2/D2 from Ru(0001)
Dissipative dynamics within the electronic friction approach: the femtosecond laser desorption of H2/D2 from Ru(0001)
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DOI：
10.1039/c0cp02086a
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Saalfrank, Peter
中科院分区：
文献类型：
--
作者：
Fuechsel, Gernot;Klamroth, Tillmann;Saalfrank, Peter
基于朗之万动力学的电子摩擦方法用于描述飞秒激光诱导 H-2 和 D-2 从 H(D) 覆盖的 Ru(0001) 表面解吸的多维（六维）动力学。该论文使用类似的方法扩展了之前的降维模型。目前，处理力和摩擦系数是根据周期密度泛函理论（DFT）计算的，基本上是无参数的，而飞秒激光脉冲对金属表面的作用是通过使用双温度模型来处理的。我们的计算揭示了描述金属表面热电子介导光反应的各种绝热、非绝热和阿伦尼乌斯/克莱默斯型动力学模型的性能和有效性。多维摩擦动力学能够重现和解释已知的实验事实，例如强同位素效应、激光注量的特性缩放以及解吸物质的振动、旋转和平移能量的非均分。此外，还对平移进行了详细预测，并解决了借助振动预激励控制表面光反应的问题。
An electronic friction approach based on Langevin dynamics is used to describe the multidimensional (six-dimensional) dynamics of femtosecond laser induced desorption of H-2 and D-2 from a H(D)-covered Ru(0001) surface. The paper extends previous reduced-dimensional models, using a similar approach. In the present treatment forces and frictional coefficients are calculated from periodic density functional theory (DFT) and essentially parameter-free, while the action of femtosecond laser pulses on the metal surface is treated by using the two-temperature model. Our calculations shed light on the performance and validity of various adiabatic, non-adiabatic, and Arrhenius/Kramers type kinetic models to describe hot-electron mediated photoreactions at metal surfaces. The multidimensional frictional dynamics are able to reproduce and explain known experimental facts, such as strong isotope effects, scaling of properties with laser fluence, and non-equipartitioning of vibrational, rotational, and translational energies of desorbing species. Further, detailed predictions regarding translations are made, and the question for the controllability of photoreactions at surfaces with the help of vibrational preexcitation is addressed.