Reduced and full system-bath quantum dynamics of IR-driven adsorbate vibrations

红外驱动吸附物振动的减少和完整系统浴量子动力学

基本信息

批准号：
230315027
负责人：
Professor Dr. Peter Saalfrank
金额：
--
依托单位：
Lehrstuhl für Theoretische Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2012
资助国家：
德国
起止时间：
2011-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/230315027?language=en
关键词：
Reduced full system bath quantum

项目摘要

Adsorbate vibrations, excited by infrared (IR) light, play a role in many fields of chemistry and physics. Examples refer to spectroscopy, mode-selective chemistry, information technology, or energy transfer and storage at interfaces. As "open quantum systems", vibrations at surfaces are also of considerable fundamental interest, notably in the context of so-called "non-Markovian" behaviour and the preservation of coherences in molecular ensembles over long time periods. In the current project, the dynamics of elementary processes connected to the excitation and subsequent, relaxation of vibrations of atoms or molecules at semiconductor or insulator surfaces are studied theoretically with the help of quantum dynamical methods. Based on our work of the first funding period, the following aims will be addressed along these lines: For the example of hydrogen and deuterium adsorbed on a reconstructed silicon surface, (1) a systematic test of "reduced", open-system density matrix theory shall be performed in comparison to an "exact" treatment of system-bath dynamics using a time-dependent Schrödinger equation; (2) model Hamiltonians developed thus far shall be extended and efficient, numerical wavefunction-based methods shall be applied to treat IR excitation and relaxation caused by vibration-phonon coupling; (3) the interplay between IR excitation and relaxation shall be studied, notably towards the goal of mode-selective excitation in a dissipative environment. (4) For a second model system, carbon monoxide on a NaCl(100) surface, coarse grained density matrix models shall be developed to describe IR excitation and subsequent vibrational energy transfer in ensembles of adsorbed molecules. Here in particular, the phenomenon of "energy pooling" is of interest, for which current experiments show the occurrence of vibrationally very highly excited CO molecules.

由红外 (IR) 光激发的吸附振动在化学和物理的许多领域发挥着作用，例如光谱学、模式选择化学、信息技术或界面处的能量传输和存储。表面振动也具有相当大的基础意义，特别是在所谓的“非马尔可夫”行为和分子系综在很长一段时间内保持相干性的背景下，在当前的项目中，与基本过程的动力学相关。借助量子动力学方法，从理论上研究半导体或绝缘体表面原子或分子的激发和随后的振动弛豫，基于我们第一期资助期间的工作，将沿着这些思路解决以下目标：吸附在重建硅表面上的氢和氘，（1）应进行“简化”开放系统密度矩阵理论的系统测试，与使用时间相关的系统浴动力学“精确”处理进行比较薛定谔方程；（2）应扩展和有效地应用基于数值波函数的哈密顿方程来处理由振动声子耦合引起的红外激发和弛豫；（3）应将红外激发和弛豫之间的相互作用研究，特别是为了在耗散环境中进行模式选择性激发的目标 (4) 对于第二个模型系统，即 NaCl(100) 表面上的一氧化碳，应开发粗粒密度矩阵模型来实现。描述了吸附分子集合中的红外激发和随后的振动能量转移，其中“能量汇集”现象尤其令人感兴趣，目前的实验表明存在振动非常高度激发的 CO 分子。