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Simulations of Competing Phases and Quantum Criticality in Strongly Correlated Materials

强相关材料中竞争相和量子临界点的模拟

基本信息

批准号：
1728457
负责人：
Ka Ming Tam
金额：
$ 34.5万
依托单位：
Louisiana State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2022-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1728457&HistoricalAwards=false
关键词：
Simulations Competing Phases Quantum Criticality

项目摘要

NONTECHNICAL SUMMARYThe Division of Materials Research funds this award that supports research and education on the development of new formalisms, algorithms and codes, and on their use in the study of complex behavior of constituent electrons in materials.One of the most fascinating areas of materials science is the study of how electrons organize in materials, giving rise to different quantum phases, such as metals, insulators, semiconductors or superconductors, which are characterized by different and technologically important properties. Quantum criticality occurs when multiple such phases coexist and compete in a material. At the boundaries between these phases, it is possible that no well-established phase exists; as a result, completely new states of matter may emerge. These new phases and their competition is not only fascinating from a fundamental standpoint, but may also hold the promise of new applications and functionalities since at a tenuous balance between phases, the application of an electric or magnetic field, or pressure, or changes in the chemical composition of the material may dramatically change its properties. New functionalities may then emerge as the system "switches" between the different states. The project entails developing relevant methodology, and will use supercomputers to study these quantum critical states of matter, the competition between different phases, and their response to different external fields.The research will be carried out in collaboration with researchers in India, furthering an established international collaboration involving several present and former students. The project will also involve a number of outreach efforts developed to increase student interest and achievement in the sciences, and to encourage students to consider STEM careers. The researchers funded by the award will participate in a Beowulf Bootcamp each summer where high-school students will construct and use a small supercomputer.TECHNICAL SUMMARYThe Division of Materials Research funds this award that supports research and education on complex behaviors in correlated electronic materials, including competing phases in cuprate superconductors, heavy-Fermion systems, and disordered interacting electronic systems and superconductors. Special emphasis will be placed on identifying and studying new quantum critical points and competing phases, and the Anderson disorder-driven quantum phase transition and its competition with interactions.The goal of this project is to continue the development of new formalisms, algorithms and codes, and to use them in the study complex behavior in correlated electronic materials. The research team will focus on simulations of quantum criticality and disordered interacting models near localization. Quantum criticality is of great fundamental interest, since the associated transitions are driven by quantum rather than thermal fluctuations. The PI and his group will develop a better understanding of the competing phases in correlated and strongly disordered systems that could lead to new functionalities, including the Anderson metal-insulator transition, and other quantum phase transitions. A more complete understanding of quantum criticality may in turn lead to a better understanding of high-temperature superconductors and other technologically important materials.The project will employ an array of theoretical/computational tools including multiscale approaches, quantum Monte Carlo, and fast approximate cluster solvers, and novel methods to treat disordered interacting systems near an Anderson localization transition including the recently developed typical-medium dynamical cluster approximation used to study the Anderson localization quantum phase transition.The research will be carried out in collaboration with researchers in India, furthering an established international collaboration involving several present and former students. The project will also involve a number of outreach efforts developed to increase student interest and achievement in the sciences, and to encourage students to consider STEM careers. The researchers funded by the award will participate in a Beowulf Bootcamp each summer where high-school students will construct and use a small supercomputer.

非技术摘要材料研究部资助该奖项，支持新形式、算法和代码的开发以及它们在材料中组成电子的复杂行为研究中的应用的研究和教育。材料科学最令人着迷的领域之一是研究电子如何在材料中组织，从而产生不同的量子相，例如金属、绝缘体、半导体或超导体，其特征是不同且具有技术重要性的特性。当多个这样的相在材料中共存并竞争时，就会出现量子临界。在这些阶段之间的边界处，可能不存在明确的阶段；结果，可能会出现全新的物质状态。这些新相及其竞争不仅从基本角度来看令人着迷，而且还可能带来新应用和功能的希望，因为在相之间的脆弱平衡下，施加电场或磁场、压力或材料化学成分的变化可能会极大地改变其性能。随着系统在不同状态之间“切换”，新的功能可能会出现。该项目需要开发相关方法，并将使用超级计算机来研究这些物质的量子临界状态、不同相之间的竞争以及它们对不同外部场的响应。该研究将与印度的研究人员合作进行，进一步推进涉及几名现任和前任学生的既定国际合作。该项目还将开展一系列外展活动，以提高学生对科学的兴趣和成就，并鼓励学生考虑 STEM 职业。受该奖项资助的研究人员将每年夏天参加 Beowulf 训练营，高中生将在其中构建和使用小型超级计算机。技术摘要材料研究部资助该奖项，支持相关电子材料复杂行为的研究和教育，包括铜酸盐超导体、重费米子系统以及无序相互作用电子系统和超导体的竞争相。特别重点将放在识别和研究新的量子临界点和竞争相，以及安德森无序驱动的量子相变及其与相互作用的竞争上。该项目的目标是继续开发新的形式、算法和代码，并将它们用于研究相关电子材料中的复杂行为。研究团队将专注于量子临界性和近局域化无序相互作用模型的模拟。量子临界性具有重大的根本意义，因为相关的跃迁是由量子而不是热波动驱动的。 PI 和他的团队将更好地理解相关和强无序系统中的竞争相，这可能会带来新的功能，包括安德森金属-绝缘体转变和其他量子相变。对量子临界性的更全面的理解可能反过来会导致对高温超导体和其他技术上重要的材料的更好的理解。该项目将采用一系列理论/计算工具，包括多尺度方法、量子蒙特卡罗和快速近似簇求解器，以及处理安德森定域转变附近无序相互作用系统的新方法，包括最近开发的用于研究安德森定域的典型介质动态簇近似量子相变。该研究将与印度的研究人员合作进行，进一步推进涉及几位现在和以前的学生的既定国际合作。该项目还将开展一系列外展活动，以提高学生对科学的兴趣和成就，并鼓励学生考虑 STEM 职业。受该奖项资助的研究人员将每年夏天参加 Beowulf 训练营，高中生将在那里建造和使用小型超级计算机。

项目成果

期刊论文数量（12）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Neural Network Solver for Small Quantum Clusters

DOI：
10.3390/cryst12091269
发表时间：
2020-08
期刊：
Crystals
影响因子：
2.7
作者：
Nicholas Walker;Samuel Kellar;Yi Zhang;Ka-Ming Tam
通讯作者：
Nicholas Walker;Samuel Kellar;Yi Zhang;Ka-Ming Tam

Systematic Quantum Cluster Typical Medium Method for the Study of Localization in Strongly Disordered Electronic Systems

用于研究强无序电子系统局域化的系统量子簇典型介质方法

DOI：
10.3390/app8122401
发表时间：
2018
期刊：
Applied Sciences
影响因子：
0
作者：
Terletska, Hanna;Zhang, Yi;Tam, Ka-Ming;Berlijn, Tom;Chioncel, Liviu;Vidhyadhiraja, N.;Jarrell, Mark
通讯作者：
Jarrell, Mark

Deep learning on the 2-dimensional Ising model to extract the crossover region with a variational autoencoder