Mixed Quantum-Classical Dynamics of Quantum Energy Transfer Processes

量子能量传输过程的混合量子经典动力学

• 批准号: RGPIN-2020-05977
• 负责人: Hanna, Gabriel
• 金额: $ 2.62万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=718137
• 关键词: Mixed; Quantum; Classical; Dynamics; Energy

From predicting new phenomena to interpreting experimental findings, molecular dynamics has become an indispensable tool for both experimentalists and theorists. Adopting a classical description of matter, one can perform molecular dynamics simulations of systems containing very large numbers of particles. However, when particles exhibit wave-like properties, a classical description is no longer valid. Quantum molecular dynamics methods are available, but they are restricted to very small systems as their computational costs scale exponentially with the number of particles. To treat larger systems, one can resort to mixed quantum-classical methods, which treat a key part of the system (i.e., the subsystem) quantum mechanically and the remainder (i.e., the bath) classically. Over the years, a number of mixed quantum-classical dynamics algorithms have been developed. The most accurate of them perform very well, but at high computational costs. Recently, we developed a method that exhibits a favourable balance between computational cost and accuracy. In its present formulation, however, this method is restricted to systems whose potential energies can be expressed in polynomial form and whose subsystems quickly lose memory of the bath dynamics. Thus, the first part of our research program will focus on advancing this methodology along several directions to make it more general, accurate, and efficient. The result promises to be a very powerful tool for simulating the dynamics of mixed quantum-classical systems. The second part of our research program will focus on applying both the present and future formulations of our mixed quantum-classical methodologies to a host of quantum energy transfer/storage processes of fundamental and technological importance. Specifically, we will explore quantum heat transfer processes involved in molecular electronics and nanophononics applications, and energy storage in quantum batteries. Our goals will be to gain an in-depth understanding of the factors that influence the rates/mechanisms of the heat transfer in a variety of molecular systems, and to propose practical designs for quantum batteries. The knowledge gained by this research will ultimately aid in the development of robust, efficient, and controllable nanoscale devices for use in quantum technologies.

从预测新现象到解释实验结果，分子动力学已成为实验学家和理论家不可或缺的工具。采用物质的经典描述，可以对包含大量粒子的系统进行分子动力学模拟。然而，当粒子表现出波状特性时，经典描述就不再有效。量子分子动力学方法是可用的，但它们仅限于非常小的系统，因为它们的计算成本随着粒子数量呈指数级增长。为了处理更大的系统，可以采用混合量子经典方法，该方法用量子力学方法处理系统的关键部分（即子系统），而用经典方法处理其余部分（即浴池）。多年来，已经开发了许多混合量子经典动力学算法。其中最准确的模型表现非常好，但计算成本很高。最近，我们开发了一种在计算成本和准确性之间表现出良好平衡的方法。然而，在目前的表述中，该方法仅限于势能可以用多项式形式表示的系统，并且其子系统很快就会失去浴动力学的记忆。因此，我们研究计划的第一部分将侧重于沿着几个方向推进该方法，使其更加通用、准确和高效。结果有望成为模拟混合量子经典系统动力学的非常强大的工具。 我们研究计划的第二部分将侧重于将我们的混合量子经典方法论的当前和未来公式应用于一系列具有基础和技术重要性的量子能量传输/存储过程。 具体来说，我们将探索分子电子学和纳米声学应用中涉及的量子传热过程，以及量子电池中的能量存储。 我们的目标是深入了解影响各种分子系统中传热速率/机制的因素，并提出量子电池的实用设计。 这项研究获得的知识最终将有助于开发用于量子技术的稳健、高效和可控的纳米级设备。