Relaxation Spectroscopy and Transport in Condensed Phases

弛豫光谱和凝聚相输运

• 批准号: 9219474
• 负责人: James Skinner
• 金额: $ 33.54万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1995-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9219474&HistoricalAwards=false
• 关键词: Relaxation; Spectroscopy; Transport; Condensed; Phases

Professor James Skinner is supported by a grant from the Theoretical and Computational Chemistry Program to continue his work in studies of relaxation, spectroscopy, and transport in condensed phases. Skinner employs a model system consisting of two quantum levels coupled to a quantum mechanical bath which is used for studies of relaxation processes, and has applications to many different branches of spectroscopy. In the usual approach it is assumed that the coupling between the quantum levels and the bath is weak, and that the initial density matrix factors into a product of density matrices for the quantum levels and one for the bath. Skinner's approach differs in that his studies of the relaxation properties of the reduced density matrix do not involve either of these two assumptions. Skinner will develop a microscopic theory of inhomogeneous lineshapes in crystals which he will apply to results of several experiments. He also will develop a statistical mechanical dynamical theory of electronic spectroscopy in liquids and dense gases such as supercritical fluids. %%% The last decade has shown that disorder is responsible for many important properties of materials. In addition, the transport of electrons in condensed matter, which has important implications for biology and solar energy collection, is greatly affected by disorder. Skinner's research provides important insights at the molecular level which will lead to a clearer understanding of the way in which disorder influences the important material properties of condensed phase chemical systems.

詹姆斯·斯金纳教授得到了理论和计算化学计划的资助，继续他在松弛、光谱和凝聚相中的输运研究方面的工作。斯金纳使用了一个由两个量子能级耦合到一个用于研究弛豫过程的量子力学浴池的模型系统，并将其应用于光谱学的许多不同分支。在通常的方法中，假设量子能级和水槽之间的耦合很弱，并且初始密度矩阵因式为量子能级的密度矩阵和水槽的密度矩阵的乘积。斯金纳的方法的不同之处在于，他对约化密度矩阵的松弛性质的研究不涉及这两个假设中的任何一个。斯金纳将发展晶体中非均匀线形的微观理论，他将把这一理论应用于几个实验的结果。他还将发展液体和稠密气体(如超临界流体)中电子光谱的统计力学动力学理论。过去十年的研究表明，无序与材料的许多重要性质有关。此外，电子在凝聚态物质中的输运受到无序的很大影响，这对生物学和太阳能收集具有重要意义。斯金纳的研究在分子水平上提供了重要的见解，这将使我们更清楚地理解无序如何影响凝聚相化学体系的重要材料性质。