First Principles Description of Strongly Correlated Electrons Using Quantum Monte Carlo

技术总结该奖项支持计算和理论研究以及教育，以推进量子蒙特卡罗方法和研究强关联材料。PI将通过精确的量子蒙特卡罗计算计算折合密度矩阵，并利用这些信息开发一种方法来确定强关联材料中关联的性质。二氧化钒中金属-绝缘体转变的研究将是一个特别的研究重点。PI将使用这些方法对各种相关材料进行调查，包括铜酸盐超导体。PI的目标是开发一个关联依赖于掺杂的模型，这将导致高温超导材料的低能模型。作为这项工作的结果，执行计算的出版物和计算机代码将以开源程序QWalk的形式广泛分发。这个项目还将培训学生在材料研究的前沿领域对强关联材料进行高级计算建模。非技术总结该奖项支持计算和理论研究，以开发方法来深入了解强关联材料，这些材料在电子之间的强相互作用产生的电子运动中显示出关联。这项研究将集中在两类材料上，二氧化钒和高温超导体。人们认为，电子之间的强烈相互作用导致二氧化钒从金属转变为绝缘体。高温超导体表现出超导性，这种物质的状态可以无损耗地导电，直到观察到超导的最高温度。人们认为，电子关联是实现高温超导的重要因素。PI将发展一种基于求解量子力学基本方程--大量电子的薛定谔方程的方法。PI将使用先进的方法来求解具有最少假设的方程，这在计算上是非常密集的。PI将开发一种分析结果的方法，该方法将提供可用于开发更易于计算的简化模型的信息。作为这项工作的结果，执行计算的出版物和计算机代码都将以开放源码程序QWalk的形式广泛分发。该项目还将培训学生在材料研究的前沿领域对强关联材料的高级计算建模。

TECHNICAL SUMMARYThis award supports computational and theoretical research and education to advance quantum Monte Carlo methods and study strongly correlated materials.The PI will calculate reduced density matrices from accurate quantum Monte Carlo calculations and use the information to develop a method to determine the nature of correlations in strongly correlated materials. The study of the metal-insulator transition in Vanadium dioxide will be a specific focus of study. The PI will use the methods to peform a survey of various correlated materials, including the cuprate superconductors. The PI aims to develop a model for the dependence of correlation on doping that will lead to a low-energy model for high temperature superconductor materials.As a result of this work, both publications and computer code to perform the calculations will be broadly distributed in the form of the open source program QWalk. This project will also train students in advanced computational modeling of strongly correlated materials at the frontiers of materials research.NON-TECHNICAL SUMMARYThis award supports computational and theoretical research to develop methods to gain insight into strongly correlated materials that exhibit correlations in the motion of electrons that arise from strong interactions between electrons. The research will focus on two classes of materials, vanadium dioxide and high temperature superconductors. It is thought that strong interactions between electrons lead to vanadium dioxide turning from a metal to an insulator. The high temperature superconductors exhibit superconductivity, a state of matter which can conduct electricity without loss, up to the highest temperatures at which superconductivity has been observed. It is believed that electron correlations are an important ingredient to achieving high temperature superconductivity. The PI wil develop a method based on the solution of the fundamental equation of quantum mechanics, the Schroedinger equation for a large number of electrons. The PI will use advanced methods to solve the equation with a minmum number of assumption which is computationally very intense. The PI will develop a method for analyzing the results which will provide information that can be used to develop a simplified model that is more computationally tractable. As a result of this work, both publications and computer code to perform the calculations will be broadly distributed in the form of the open source program QWalk. This project will also train students in advanced computational modeling of strongly correlated materials at the frontiers of materials research.