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

技术摘要这一奖项支持涉及相互作用的玻色子和旋转系统的广泛计算研究的研究，这些研究对于理解密切相关的多体物理学至关重要。 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.这样的研究可以为相互作用的玻色子系统的全局相图提供定量预测，并揭示可能属于新通用类别的量子相变的性质。 PI还将研究强相关和沮丧的磁系统中的自旋液体行为，分数化，拓扑顺序和相关的量子相变。通过实验发现候选旋转液态状态的实验发现的越来越多的磁性材料。 PI将在各种量子自旋模型中使用确切的兰氏方法与密度基质重新归一化组方法相结合，以研究低能谱，拓扑脱落性和自旋旋转相关功能。 PI的目的是获得基本的见解，研究可能建立原则证明？旨在与Herbertsmithite上的实验以及某些分层的氧化物氧化物和复杂的镀糊精的实验接触的简单自旋模型中存在新型自旋液相的证据。该项目支持学生和博士后研究人员的教育经验；少数族裔学生将参与其中。该研究为多体物理学非技术摘要的新计算课​​程做出了贡献，该奖项支持计算研究和教育，该奖项将使用先进的计算技术来搜索物质的新电子状态。 PI将研究材料模型，其中最小的磁性单位不能简单地以这种方式与磁铁或抗fiferromagnet进行对齐。 任何对齐都无法在晶格上满足相邻最小的磁性单位之间的相互作用。这些沮丧的磁铁是展示新的电子物质状态的候选者。 PI的目的是使用计算来查看特定的理论上提出的物质状态是否存在于被认为与候选材料相关的模型中，例如矿物质赫伯特史密斯和高温超导体。这是基础研究，这是为我们对材料的理解和新的属性现象的理解和新的现象的智力智力基础的基础，这些基础与我们现有的现有元素的理解相同。这本身就是一种智力追求，而不是对宇宙的研究，但它也可能导致发现新现象并为未来的设备技术做出贡献。该项目支持学生和博士后研究人员的教育经验；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