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 However, when particles exhibit wave-like properties, a classical description is no longer valid.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，分子动力学已经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，当粒子表现出波的性质时，经典的描述就不再有效了。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与粒子数量呈指数级增长。为了处理更大的系统，人们可以求助于混合量子经典方法，它以量子力学的方式处理系统的关键部分（即子系统），而以经典的方式处理其余部分（即浴池）。多年来，许多混合量子-经典动力学算法被开发出来。其中最精确的算法性能非常好，但计算成本很高。最近，我们开发了一种方法，在计算成本和准确性之间取得了良好的平衡。然而，在目前的公式中，该方法仅限于势能可以用多项式形式表示并且子系统很快失去浴池动力学记忆的系统。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这种方法，使其更通用、准确和有效。该结果有望成为模拟混合量子-经典系统动力学的一个非常强大的工具。