Molecular Radiative and Relaxation Processes

加州大学欧文分校的Shaul Mukamel在相干非线性多维光谱的设计、建模和分析方面获得了化学学部理论、模型和计算方法项目的奖项。Liouville空间中的超级算子方法正在被开发，并被用作涉及快脉冲光与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，包括尖端和结载流接触的非平衡情况；(2)量子场纠缠光子的多维光谱；(3)分子生色团聚集体和量子点阵列中的电荷分离和多激子光谱特征；(4)利用柔性脉冲极化策略研究分子手性的飞秒相干反斯托克斯拉曼散射探针。使用Liouville方法描述这些和许多其他实验，并使用为多维光学电子和振动光谱创建的SPECTRON软件进行计算建模，并向研究界提供。分子对不同光束的反应取决于许多因素，例如光束在空间和时间上相互重叠的程度以及分子。PI已经开发了计算不同情况下反应的工具，例如当分子也被扫描隧道显微镜探针探测或在两根导线之间携带电流时。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。使用PI创建的方法和软件可以模拟许多最有趣的实验，这些实验涉及到接近或散射来自分子样品的光子之间的明确类型的相关性，这些分子样品甚至可以由单个分子组成。PIs的书“非线性光学原理”是该领域研究的主要指南，并在该奖项下进行了广泛的修订。在PI的指导下，学生和博士后培养了一批在这些方法上受过训练的研究人员。

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.