Computational Studies of Nonequilibrium Dynamics of Classical and Quantum Materials

技术摘要材料研究部和网络基础设施办公室为该奖项提供资金。该奖项支持涉及经典和量子模型的材料非平衡动力学的计算和理论研究和教育。PI最近的两个算法进步，一个用于经典系统，一个用于量子系统，将进一步发展并应用于特定模型。这个项目的重点是：1。与射影动力学和正向通量采样方法相关的数学基础，最近被证明适用于经典离格系统的非平衡动力学。将进一步发展投影动力学和正向磁通采样方法，并将其应用于振荡电磁场的两种模拟。一项研究将与锂离子可充电电池的快速充电有关，另一项研究将与蛋白质折叠相关的非平衡过程有关。2. 一种新的量子算法将允许研究具有比以前实时计算更大的希尔伯特空间的自旋系统。该算法将应用于研究与特定显式自旋场耦合的自旋系统的退相干和热化。非平衡动力学和平衡方法都将被研究。该方法还将使物理时间和时间之间的关系在动态蒙特卡罗模拟的量化。3. 还将进行另外两项更具推测性的研究。一项研究将扩展PI的一种新的重整化群方法，通过无序纳米材料的紧密结合模型来研究随时间变化的电子传递。第二项研究将进行实时量子模拟，以了解无处不在的经典同步现象如何在大量子系统中表现出来。该奖项还支持研究生和本科生的教育，包括少数民族和女学生，在平衡和非平衡材料过程的计算研究。此外，在本项目过程中开发的与量子和经典系统的非平衡模拟相关的计算机源代码将通过一个使用GNU通用公共许可证（版本3或更高版本）的网站向公众提供，以鼓励代码在研究和教育中重用。材料研究部和网络基础设施办公室为该奖项提供资金。该奖项支持与材料非平衡动力学相关的计算和理论研究和教育。给电子设备的电池充电是一个非平衡过程。与接近量子系统经典行为相关的过程是非平衡动力学的附加形式，称为退相干和热化。进行非平衡过程的计算机模拟可以更好地理解材料的性质。这些研究的最终目标可能是让电池更快地充电，或者在更长的时间内保持电子量子力学状态的完整性。需要复杂的算法使计算机模拟大型非平衡系统的长期研究成为可能。该奖项支持开发用于材料非平衡过程的创新计算机算法，并将这些算法应用于特定模型，以更好地了解材料的动力学。该奖项支持本科生和研究生的教育，包括少数民族和女性学生，在非平衡材料过程的计算研究。在这个项目过程中开发的与量子和经典系统的非平衡模拟相关的计算机代码将免费提供，鼓励代码重用用于研究和教育。

TECHNICAL SUMMARYThe Division of Materials Research and the Office of Cyberinfrastructure contribute funds to this award. This award supports computational and theoretical research and education on non-equilibrium dynamics of materials involving classical and quantum models. Two recent algorithmic advances by the PI, one for classical systems and one for quantum systems, will be further developed and applied to specific models. The main thrusts of this project are: 1. The mathematical underpinnings necessary to bridge disparate time scales in simulations, related to Projective Dynamics and Forward Flux Sampling methods, have recently been shown to be applicable to non-equilibrium dynamics of classical off-lattice systems. The Projective Dynamics and Forward Flux Sampling methods will be further developed and applied to two simulations with oscillating electromagnetic fields. One study will be related to fast charging for Lithium-ion rechargeable batteries, the other to non-equilibrium processes relevant to the folding of proteins. 2. A novel quantum algorithm will allow studies of spin systems with a much larger Hilbert space than previously accessible to real-time calculations. This algorithm will be applied to study decoherence and thermalization of spin systems coupled to specific explicit spin baths. Both non-equilibrium dynamics and the approach to equilibrium will be investigated. The methodology will also enable quantification of the relation between physical time and time in dynamic Monte Carlo simulations. 3. Two additional studies of a more speculative nature will also be performed. One study will expand a new Renormalization Group method of the PI to investigate time-dependent electron transport through tight-binding models of nanomaterials with disorder. The second study will be to perform real-time quantum simulations in order to understand how the ubiquitous classical phenomenon of synchronization is manifest in large quantum systems. This award also supports education of graduate and undergraduate students, including minority and female students, in the computational study of equilibrium and non-equilibrium materials processes. In addition, select computer source codes developed in the course of this project and related to non-equilibrium simulations of quantum and classical systems will be made available to the general public through a web site utilizing a GNU General Public License, version 3 or later, in order to encourage code reuse for both research and education. NONTECHNICAL SUMMARYThe Division of Materials Research and the Office of Cyberinfrastructure contribute funds to this award.The award supports computational and theoretical research and education related to the non-equilibrium dynamics of materials. Recharging the battery of an electronic device is a non-equilibrium process. Processes related to the approach toward classical behavior of quantum systems are additional forms of non-equilibrium dynamics, which are called decoherence and thermalization. Performing computer simulations of non-equilibrium processes provides a better understanding of materials properties. The ultimate goals of such studies may be the faster charging of a battery or maintaining the integrity of a quantum mechanical state of electrons for a longer time. Sophisticated algorithms are required to enable computer simulations of long-time studies of large non-equilibrium systems. This award supports developing innovative computer algorithms for non-equilibrium processes in materials, and to apply these algorithms to specific models to obtain a better understanding of the dynamics of materials. This award supports the education of undergraduate and graduate students, including minority and female students, in the computational studies of non-equilibrium materials processes. Computer codes related to non-equilibrium simulations of quantum and classical systems that are developed in the course of this project will be made freely available encouraging code reuse for research and education.