Quantum Monte Carlo Using Multicore Processors: Enabling Simulations in Inhomogeneous Environments

发展对强关联电子系统（SCES）的理解和预测能力是一个快速发展的领域，它严重依赖于更快的计算以持续进步。SCES形成了关键材料能力的基础，包括高温超导性，核燃料，新型热电材料，以及冷原子气体中的奇异和有前途的行为。SCES是很难在理论上建模的材料，因为它们的电子成分的高度依赖于时间的波动。 一个重要的新兴技术是多核处理器，其中越来越多的CPU（“核心”）并置在单个芯片上，因此非常紧密地耦合。 计算量的加速（预期）包括一个有希望的途径，以回避众所周知的半导体技术中的摩尔定律的崩溃。这个项目涉及先进的计算物理方法，“量子蒙特卡罗”和“密度泛函理论”的发展，用于研究SCES属性。 这些新方法的能力将大大提高了制定有效的战略，他们的新兴多核处理器上的实施。 这项工作跨越了凝聚态和原子物理之间的知识界限，也跨越了物理学、应用数学和计算机科学之间的知识界限。 这些应用将探索相互作用对磁性，金属-绝缘体和超导转变产生的物质新量子态的影响。 一个特别的项目重点将是空间不均匀性（“缺陷”）对量子系统有序相的影响。 除了推进计算物理学和材料科学的研究外，这项工作对培养研究生和博士后研究人员跨学科研究工具具有更广泛的影响。 主要研究人员也在让本科生甚至高中生参与研究方面做出了巨大努力，他们将继续进行这个项目。

Developing an understanding of, and a predictive capability for, strongly correlated electron systems (SCES), is a rapidly evolving field that relies critically on faster computation for continued progress. SCES form the basis of crucial materials capabilities, including high temperature superconductivity, nuclear fuels, new classes of thermoelectrics, and the exotic and promising behavior seen in cold atomic gases. SCES are difficult materials to model theoretically because of the highly time-dependent fluctuations of their electronic constituents. An important emerging technology is the multicore processor, where an increasingly large number of CPUs ("cores") are juxtaposed on a single chip and thus are extremely closely coupled. The resulting (expected) speedup in computational throughput comprises a promising path to sidestep the well publicized breakdown of Moore's law in semiconductor technology.This project involves the development of advanced computational physics methods, "Quantum Monte Carlo" and "Density Functional Theory," for studying SCES properties. The capabilities of these new approaches will be greatly enhanced by the formulation of efficient strategies for their implementation on emerging multicore processors. This work crosses the intellectual boundary between condensed matter and atomic physics, and also between physics, applied mathematics, and computer science. The applications will explore effects of interactions on novel quantum states of matter which arise from magnetic, metal-insulator, and superconducting transitions. A particular project focus will be on the effect of spatial inhomogeneities ("defects") on ordered phases of quantum systems. In addition to advancing research in computational physics and materials science, this work has broader impacts to training graduate students and postdoctoral researchers in interdisciplinaryresearch tools. The Principal Investigators have also a substantial effort in involving undergraduate students and even high school students in research, which they will continue with this project.