Molecular Radiative and Relaxation Processes

加州大学欧文分校的 Shaul Mukamel 因相干非线性多维光谱的设计、建模和分析而获得化学系理论、模型和计算方法项目的奖项。刘维尔空间的超级算子方法正在开发中，并用作涉及快速脉冲光和物质相互作用的应用的计算工具：（1）相干和非相干飞秒单分子光谱，包括具有尖端和结载流接触的非平衡环境，（2）具有量子场纠缠光子的多维光谱，（3）分子发色团聚集体和量子中的电荷分离和多激子光谱特征点阵列，以及（4）使用灵活的脉冲偏振策略的分子手性飞秒相干反斯托克斯拉曼散射探针。 这些实验和许多其他实验均使用刘维尔方法进行描述，并使用为多维光学电子和振动光谱创建并提供给研究界的软件 SPECTRON 进行计算建模。 分子对不同光束的响应取决于许多因素，例如光束彼此重叠的程度以及分子在空间和时间上的重叠程度。 PI 开发了工具来计算不同情况下的响应，例如当分子也被扫描隧道显微镜尖端探测或在两条电线之间承载电流时。 每个光束也可以是一系列快速重复的脉冲，丰富了可以引起的反应集合。 许多最有趣的实验可以使用 PI 创建的方法和软件进行模拟，涉及接近分子样本或从分子样本散射的光子之间的确定类型的相关性，分子样本甚至可以由单个分子组成。 PI 的著作《非线性光学原理》是该领域研究的主要指南，并且正在根据该奖项进行广泛的修订。 由 PI 指导的学生和博士后研究员培养了稳定的接受这些方法培训的研究人员。

Shaul Mukamel of the University of California Irvine is supported by an award from the Theory, Models and Computational Methods program in the Chemistry Division for the design, modeling and analysis of coherent nonlinear multidimensional spectroscopies. Superoperator approaches in Liouville space are being developed and used as computational tools for applications involving interactions of fast-pulsed light and matter: (1) Coherent and incoherent femtosecond single-molecule spectroscopy, including non-equilibrium circumstances with tip and junction current-carrying contacts, (2) multidimensional spectroscopy with entangled photons of quantum fields , (3) charge separation and multi-exciton spectroscopic signatures in molecular chromophore aggregates and quantum dot arrays, and (4) femtosecond coherent anti-Stokes Raman scattering probes of molecular chirality using flexible pulse-polarization strategies. These and numerous other experiments are described using the Liouville approach, and computationally modeled using software SPECTRON created for multidimensional optical electronic and vibrational spectroscopy and made available to the research community. The response of a molecule to different light beams depends on many factors, such as how much the beams overlap with each other and the molecule in both space and time. The PI has developed the tools to calculate the responses under different circumstances, such as when the molecule is also being probed by a scanning tunneling microscope tip or is carrying current between two electrical leads. Each beam can also be a series of pulses repeated very quickly, enriching the collection of responses that can be evoked. Many of the most interesting experiments that can be simulated using the methods and software created by the PI involve definite types of correlations between photons approaching or scattering from the molecular sample, which can consist of even a single molecule. The PIs book "The Principles of Nonlinear Optics" is the principal guidebook for research in this community and is undergoing extensive revision under this award. A steady flow of researchers trained in these methods is produced by the students and postdoctoral fellows mentored by the PI.