RUI: Theoretical (Numerical) Investigations of Novel Quantum Phases and Transitions in Strongly Interacting Systems

RUI：强相互作用系统中新型量子相和跃迁的理论（数值）研究

• 批准号: 0906816
• 负责人: Donna Sheng
• 金额: $ 37.5万
• 依托单位: The University Corporation, Northridge
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0906816&HistoricalAwards=false
• 关键词: RUI; Theoretical; Numerical; Investigations; Novel

TECHNICAL SUMMARYThis award supports research involving an extensive computational study of interacting boson and spin systems which are of fundamental importance in understanding strongly correlated many-body physics. The research aims for fundamental insights into that may be realized in ultracold atoms trapped in optical lattices and frustrated magnets.The PI aims to study boson Hubbard models with frustrated hopping and long range repulsions on triangular and other lattice systems to understand the microscopic conditions for realizing new quantum phases including different supersolid phases, a Mott-insulator, and possible spin-liquid phases. Such an investigation can result in quantitative predictions for the global phase diagram of interacting boson systems and reveal the nature of the quantum phase transitions which may belong to a new universality class. The PI will also study the spin liquid behavior, fractionalization, topological order and related quantum phase transitions in strongly correlated and frustrated magnetic systems. There are a growing number of magnetic materials discovered by experiment which exhibit candidate spin-liquid states. The PI will combine the exact Lanczos method with density matrix renormalization group methods to study the low energy spectrum, topological degeneracy, and spin-spin correlation function in various quantum spin models. The PI aims to gain fundamental insights and the research may establish ?proof of principle? evidence for the existence of novel spin liquid phases in simple spin models on kagome and square lattices aiming to make contact with experiments on Herbertsmithite and certain layered vanadium oxides and complex vanadium phosphates. This project supports educational experiences for students and postdoctoral researchers; minority students will be involved. The research contributes to a new computational course on many-body physics NON-TECHNICAL SUMMARYThis award supports computational research and education that will use advanced computational techniques to search for new electronic states of matter. The PI will study models for materials in which the smallest units of magnetism cannot simply align in such a way to become a magnet or an antiferromagnet. The interactions between neighboring smallest units of magnetism cannot be satisfied on the crystal lattice by any alignment. These frustrated magnets are candidates to exhibit new states of electronic matter. The PI aims to use computation to see whether specific theoretically proposed states of matter exist in models that are believed to be relevant to candidate materials, for example the mineral Herbertsmithite and high temperature superconductors.This is fundamental research that contributes to the intellectual foundations of our understanding of materials and new electronic states of matter that exhibit properties and exotic phenomena that lie outside our current understanding. This is an intellectual pursuit in its own right no less fascinating than the study of the universe, but it may also lead to the discovery of new phenomena and to contribute to future device technologies.This project supports educational experiences for students and postdoctoral researchers; minority students will be involved. The research contributes to a new computational course on many-body physics

技术摘要该奖项支持涉及对相互作用的玻色子和自旋系统进行广泛的计算研究的研究，这对于理解强相关的多体物理学至关重要。该研究的目的是对被困在光学晶格和受挫磁体中的超冷原子中可能实现的基础性见解进行深入了解。该项目负责人的目的是研究三角形和其他晶格系统上具有受挫跳跃和长程排斥的玻色子哈伯德模型，以了解实现的微观条件新的量子相，包括不同的超固相、莫特绝缘体和可能的自旋液相。这样的研究可以对相互作用的玻色子系统的全局相图进行定量预测，并揭示可能属于新的普遍性类别的量子相变的本质。 PI 还将研究强相关和受抑磁系统中的自旋液体行为、分级、拓扑顺序和相关量子相变。通过实验发现越来越多的磁性材料表现出候选自旋液体态。 PI将精确Lanczos方法与密度矩阵重正化群方法相结合，研究各种量子自旋模型中的低能谱、拓扑简并性和自旋-自旋相关函数。 PI 旨在获得基本见解，研究可以建立“原理证明”。 Kagome 和方晶格的简单自旋模型中存在新型自旋液相的证据，旨在与赫伯特铁矿和某些层状钒氧化物和复合磷酸钒的实验建立联系。该项目支持学生和博士后研究人员的教育体验；少数族裔学生将参与其中。该研究为多体物理学的新计算课​​程做出了贡献。非技术性摘要该奖项支持计算研究和教育，将使用先进的计算技术来寻找物质的新电子态。 PI 将研究材料模型，其中最小的磁性单位不能简单地排列成磁铁或反铁磁体。 晶格上的任何排列都无法满足相邻最小磁性单元之间的相互作用。这些受挫的磁铁是展示电子物质新状态的候选者。 PI 旨在利用计算来查看被认为与候选材料（例如矿物赫伯特铁矿和高温超导体）相关的模型中是否存在特定的理论提出的物质状态。这是一项基础研究，有助于为我们的知识基础做出贡献。对材料和物质新电子态的理解，这些材料和新电子态表现出我们当前理解之外的特性和奇异现象。这本身就是一种智力追求，其魅力不亚于宇宙研究，但它也可能导致新现象的发现并为未来的设备技术做出贡献。该项目为学生和博士后研究人员提供教育体验；少数族裔学生将参与其中。该研究为多体物理学的新计算课​​程做出了贡献