Quantum Mechanics and Dynamics of Open Polyatomic Systems

我们建议从计算和理论上研究与外部环境耦合的多原子(大)分子系统的光致量子动力学的各个方面。这样的体系在化学中无处不在，影响着生活的方方面面。事实上，分子与阳光的相互作用，例如在光合作用中，是能量传递到地球上生命的主要来源。在所有待研究的情况下，我们将通过发展正式的理论和建立包含所研究系统的基本物理化学的模型来进行。当被认为具有启发性时，将调用更复杂的建模。这项拟议的工作是理论和计算化学方面的最先进工作，利用了最现代的并行计算机设施。此类研究往往先于并预示着技术和工业的发展，为加拿大在重要的先进技术应用方面提供了优势。预计拟议的方案还将提供研究环境和研究挑战，这些环境和研究挑战对培训现代、高素质人才至关重要。除了光-物质相互作用的基本问题外，我们还将考虑两个主要方向：(A)动态过程的相干控制是通过量子干涉效应控制分子过程的基本方法。这种方法基于我们几十年来所做的工作，在小型孤立量子系统中取得了巨大的成功。相比之下，控制耦合到外部环境(例如，在溶液中或在蛋白质基质中)的大分子是一个肥沃的领域，我们建议详细探索。预计这一结果将显著扩大使用量子干涉效应对化学过程进行控制的范围，量子干涉效应是下个世纪的一项新兴技术。(B)开放量子系统由主方程描述，其内在地服从广泛的近似集合(长期与非长期、马尔可夫与非马尔可夫、整体与局部耦合、低阶微扰理论等)。近似的选择对所产生的动力学有深远的影响。我们建议进行广泛的研究，以探索这些光合作用系统的近似方案的有效性领域。这里重要的是系统和环境之间的耦合的实际性质，使用各种方法进行探索。预计这些结果将大大有助于主方程方法在光收集过程中的有效性和适用性。此外，我们还将研究与光合作用系统作为光子探测器的能力有关的问题，这是一个具有根本意义的问题。

We propose to study, both computationally and theoretically, various aspects of light-induced quantum dynamics of polyatomic (large) molecular systems that are coupled to an external environment. Such systems are ubiquitous in Chemistry, affecting all aspects of life. Indeed, the interaction of molecules with sunlight, in photosynthesis for example, is the primary source by which energy is transmitted to life on earth. In all cases to be studied we will proceed by developing formal theories, and building models containing the essential physical chemistry of the system examined. More complex modeling will be invoked when deemed enlightening. The work proposed is state-of-the-art in theoretical and computational  chemistry, taking advantage of the most modern of parallel computer facilities. Such research often precedes and heralds developments in technology and industry, providing Canada with the edge in important advanced technological applications. The proposed program is also expected to provide the research environment and research challenges that are vital to the training of modern, highly qualified personnel. In addition to basic issues in light-matter interactions we will consider two major directions: (a)  Coherent Control of Dynamic Processes is a foundational approach to controlling molecular processes via quantum interference effects. The methodology, based upon work that we have done over several decades, has been highly successful for small, isolated quantum systems. By contrast, control of larger molecules that are coupled to external environments (e.g., in solution or in a protein matrix)  is a fertile field that we propose to explore in detail. The results are expected to significantly expand the range of control over processes in chemistry using quantum interference effects, an emergent technology for the coming century. (b) Open Quantum Systems are described by master equations, which are inherently subject to a wide collection of approximations (secular vs. nonsecular, Markovian vs. Non-Markovian, global vs. local couplings, low order perturbation theories, etc.). The choice of approximation has a profound influence on the resultant dynamics. We propose extensive studies designed to explore domains of validity of these approximate schemes for photosynthetic systems. Of importance here is the actual nature of the coupling between the system and environment, explored using a variety of methods. The results are expected to contribute significantly to the range of validity and applicability of master equation methods for light harvesting processes.  In addition, we will examine issues related to the ability of photosynthetic systems to act as photon detectors, an issue of fundamental significance.