Molecular Radiative and Relaxation Processes

分子辐射和弛豫过程

• 批准号: 1361516
• 负责人: Shaul Mukamel
• 金额: $ 51万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1361516&HistoricalAwards=false
• 关键词: Molecular; Radiative; Relaxation; Processes

Shaul Mukamel of the University of California, Irvine is funded by the Chemical Theory, Models and Computational Methods program in the Chemistry division for research to develop techniques that are used to analyze the precise ways molecules absorb and redistribute light. This type of process happens during photosynthesis. Understanding the precise ways that solar energy is converted to chemical energy can help in the design of new devices which artificially convert light to more useful forms of energy. In addition, the detection of individual photons, particles of light which have interacted with molecules, can reveal a great deal of information about the structure and motion of the atoms which make up those molecules. By applying a series of short light pulses to a molecule, the investigators are finding ways to extract additional information about that molecule's structure and function. Additional research explores the use of entangled photons, a very promising tool for quantum computing, secure communication methods and other possible applications. New imaging methods that might be helpful in revealing the details of biological cells are also being developed. All of these studies are carried out in collaboration with other investigators who design equipment and experiments that are used to test the insights revealed by these theoretical studies. The work has a broad impact on the experimental science community through the development of new language and concepts that help to guide scientist's understanding of the fundamental nature of the process by which light interacts with matter. The investigators freely share the software they develop through the web.The response of complex molecules to sequences of ultrafast optical laser pulses provides a multidimensional view of electronic and vibrational dynamics and of correlations. Models and computational tools are developed for the design, interpretation and analysis of these signals. Quantum properties of light, such as photon entanglement, receive special consideration as tools for probing molecules and chromophore aggregates. In another project, nonadiabatic dynamics is studied by carefully designed coherent Raman signals. The interplay of temporal and spectral resolution in stimulated Raman signals is being investigated. New detection schemes that combine coincidence measurements of individual photons and interferometry can then be predicted. Experimental techniques involving novel pulse sequences are being designed, and theoretical and computational tools for their analysis are developed and broadly applied. Some of the applications are to complex molecules in the condensed phase, to excitons in semiconductor quantum dots, and to the elementary charge and energy migration processes in light harvesting in photosynthetic antennae and reaction centers.In particular, superoperator Green's function formalism is being developed that allows the computation of the response of molecules to both quantum and stochastic light. New spectroscopic signals that make use of entangled and squeezed photons offer temporal and spectral resolutions not possible with classical light. These techniques are being applied to the study of excitons in molecular aggregates. Measurements of the effect of interactions with molecules on photon statistics are also explored as a novel spectroscopic tool. Incoherent detection of coherent signals by fluorescence which can allow the study of single molecules is being investigated. A highly-intuitive loop diagram representation is developed for the design of pulse sequences by utilizing pulse shaping, phase control and molecular chirality. Generalized signals involving the combination of several impulsive excitations and measurements that can probe both the response and spontaneous fluctuations in classical and quantum systems at steady states are predicted and connected to nonlinear fluctuation theorems. New many-body approaches for describing and calculating excited states with multiple electron and hole particles are being developed using a composite Boson (co-boson) algebraic representation. The tedious explicit computation of multi-exciton wavefunctions usually required for predicting nonlinear signals is, thus, avoided with this new approach.

加州大学欧文分校的 Shaul Mukamel 获得化学系化学理论、模型和计算方法项目的资助，用于研究开发用于分析分子吸收和重新分配光的精确方式的技术。这种类型的过程发生在光合作用期间。了解太阳能转化为化学能的精确方式有助于设计新设备，将光人工转化为更有用的能量形式。此外，对单个光子（与分子相互作用的光粒子）的检测可以揭示有关构成这些分子的原子的结构和运动的大量信息。通过对分子施加一系列短光脉冲，研究人员正在寻找提取有关该分子结构和功能的附加信息的方法。其他研究探索了纠缠光子的使用，这是一种非常有前途的量子计算、安全通信方法和其他可能应用的工具。可能有助于揭示生物细胞细节的新成像方法也正在开发中。所有这些研究都是与其他研究人员合作进行的，他们设计了设备和实验，用于测试这些理论研究揭示的见解。这项工作通过开发新的语言和概念，帮助指导科学家理解光与物质相互作用过程的基本性质，对实验科学界产生了广泛的影响。研究人员通过网络自由共享他们开发的软件。复杂分子对超快光学激光脉冲序列的响应提供了电子和振动动力学以及相关性的多维视图。开发模型和计算工具用于这些信号的设计、解释和分析。 光的量子特性，例如光子纠缠，作为探测分子和发色团聚集体的工具受到特别考虑。在另一个项目中，通过精心设计的相干拉曼信号研究非绝热动力学。受激拉曼信号中时间分辨率和光谱分辨率的相互作用正在被研究。然后可以预测结合单个光子的符合测量和干涉测量的新检测方案。涉及新颖脉冲序列的实验技术正在设计中，并且用于其分析的理论和计算工具正在开发并广泛应用。其中一些应用涉及凝聚相中的复杂分子、半导体量子点中的激子以及光合作用天线和反应中心中光收集中的基本电荷和能量迁移过程。特别是，超级算子格林函数形式主义正在开发中允许计算分子对量子光和随机光的响应。利用纠缠和压缩光子的新光谱信号提供了经典光无法实现的时间和光谱分辨率。这些技术正在应用于分子聚集体中激子的研究。与分子相互作用对光子统计的影响的测量也被探索作为一种新颖的光谱工具。正在研究通过荧光对相干信号进行非相干检测，从而可以研究单分子。通过利用脉冲整形、相位控制和分子手性，开发了一种高度直观的循环图表示，用于脉冲序列的设计。广义信号涉及多个脉冲激励和测量的组合，可以探测稳态下经典和量子系统的响应和自发涨落，并与非线性涨落定理相关联。正在开发使用复合玻色子（共玻色子）代数表示来描述和计算多个电子和空穴粒子的激发态的新多体方法。因此，这种新方法避免了预测非线性信号通常所需的繁琐的多激子波函数显式计算。

项目成果

A Quantum Chemical Interpretation of Two-Dimensional Electronic Spectroscopy of Light-Harvesting Complexes

• DOI: 10.1021/jacs.7b02130
• 发表时间: 2017-06-07
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Segatta, Francesco;Cupellini, Lorenzo;Mennucci, Benedetta
• 通讯作者: Mennucci, Benedetta

Utilizing Microcavities To Suppress Third-Order Cascades in Fifth-Order Raman Spectra

利用微腔抑制五阶拉曼光谱中的三阶级联

• DOI: 10.1021/acs.jpclett.7b01129
• 发表时间: 2017
• 期刊: The Journal of Physical Chemistry Letters
• 作者: Zhang, Zhedong;Bennett, Kochise;Chernyak, Vladimir;Mukamel, Shaul
• 通讯作者: Mukamel, Shaul

On the Simulation of Two-dimensional Electronic Spectroscopy of Indole-containing Peptides

• DOI: 10.1111/php.12770
• 发表时间: 2017-11-01
• 期刊: PHOTOCHEMISTRY AND PHOTOBIOLOGY
• 影响因子: 3.3
• 作者: Giussani, Angelo;Marcheselli, Jacopo;Nenov, Artur
• 通讯作者: Nenov, Artur

Hybrid femtosecond/picosecond pure-rotational coherent anti-Stokes Raman scattering with chirped probe pulses: Hybrid femtosecond/picosecond pure-rotational coherent anti-Stokes Raman scattering with chirped probe pulses

具有啁啾探测脉冲的混合飞秒/皮秒纯旋转相干反斯托克斯拉曼散射：具有啁啾探测脉冲的混合飞秒/皮秒纯旋转相干反斯托克斯拉曼散射

• DOI: 10.1002/jrs.5262
• 发表时间: 2017
• 期刊: Journal of Raman Spectroscopy
• 影响因子: 2.5
• 作者: Yang, Chaobo;Escofet-Martin, David;Dunn-Rankin, Derek;Chien, Yu-Chien;Yu, Xin;Mukamel, Shaul
• 通讯作者: Mukamel, Shaul