Ultrafast Nonlinear and Coherent Spectroscopic Studies of Molecular Motion in Liquids

贝格是由实验物理化学计划的支持，研究 在液体和玻璃动力学的基本问题，使用组合 实验/理论方法。 广泛的粘度范围 在过冷液体将用于探索起源， 在50飞秒内动态特征的时间发展， 25纳秒的窗口，可用于超快激光方法。 飞秒 技术和相关理论将用于研究，包括 探讨了惯性和扩散动力学，动力学的发展， 液体玻璃化转变附近的不均匀性，以及液体是否 动态可以用“模式”来描述。 的一个基本特征 这个项目是比较不同的动态测量， 相同的系统。 这项研究的结果预计将 有助于了解有用的发展一个全面的分子 液体和玻璃的集体动力学理论。 许多技术上重要的过程都受到动力学的影响 简单的液体或其他无序的物质。例如，材料 例如聚合物、无机玻璃和生物材料， 以完全或部分流体状态处理。 新的见解的 过冷液体的性质和液体玻璃化转变， 该项目的结果可能会影响材料的设计和加工 技术.

Berg is supported by the Experimental Physical Chemistry Program to study fundamental problems in liquid and glass dynamics using a combined experimental/theoretical approach. The broad viscosity range available in supercooled liquids will be utilized for exploring the origin and temporal development of dynamical features within the 50 femtosecond to 25 nanosecond window accessible to ultrafast laser methods. Femtosecond techniques and related theory will be employed for studies that include probes of intertial and diffusive dynamics, the development of dynamic inhomogeneity near the liquid-glass transition, and whether liquid dynamics can be described in terms of `modes.` An essential feature of this project is the comparison of different dynamical measurements within the same system. The outcomes from this research are expected to contribute understanding useful in developing a comprehensive molecular theory of the collective dynamics of liquids and glasses. Many technologically important processes are influenced by the dynamics of simple liquids or other disordered materials. For example, materials such as polymers, inorganic glasses, and biological materials are used or processed in a fully or partially fluid state. New insights into the nature of supercooled liquids and the liquid-glass transition that will result from this project could impact materials design and processing technologies.