Massively parallel simulations of strong electronic correlations: Realistic coulomb vertex and multiplet effects

强电子相关性的大规模并行模拟：真实的库仑顶点和多重态效应

• 批准号: 175301444
• 负责人: Professor Dr. Erik Koch
• 金额: --
• 依托单位: PGI-1 / IAS-1: Quanten-Theorie der Materialien
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/175301444?language=en
• 关键词: Massively; parallel; simulations; strong; electronic

Strongly correlated systems hold the promise to provide the basis for devices in which not only charge but also spin and orbital degrees of freedom can be controlled. The realistic description of many-body effects is, however, still one of the grand-challenges of modern condensedmatter physics: The combination of ab-initio methods based on density-functional theory and the many-body dynamical mean-field theory (the LDA+DMFT method) has in principle the ability of describing strongly correlated materials. In practice, calculations are limited to simple models with few orbitals and an approximate local Coulomb vertex. The work proposed in this project will take crucial steps towards the accurate and effective simulation of the properties of strongly correlated materials: (i) optimization of the construction of realistic Hamiltonians (many-body basis set and screened Coulomb vertex); (ii) development of a general (massively parallel) LDA+DMFT framework with multiple quantum Monte Carlo solvers to deal with complex many-body Hamiltonians, including the realistic description of multiplet effects; (iii) systematic study of series of representative materials (transition-metal oxides and organics), with the ultimate goal of establishing a standard set of benchmark correlated systems.

强相关系统有望为不仅可以控制电荷而且可以控制自旋和轨道自由度的设备提供基础。然而，多体效应的真实描述仍然是现代凝聚态物理的重大挑战之一：基于密度泛函理论的从头计算方法与多体动力学平均场理论（LDA+DMFT方法）的结合原则上具有描述强相关材料的能力。在实践中，计算仅限于具有很少轨道和近似局部库仑顶点的简单模型。该项目提出的工作将为准确有效地模拟强相关材料的特性采取关键步骤：（i）优化现实哈密顿量的构造（多体基组和筛选库仑顶点）； (ii) 开发具有多个量子蒙特卡罗求解器的通用（大规模并行）LDA+DMFT 框架，以处理复杂的多体哈密顿量，包括多重效应的真实描述； (iii) 对一系列代表性材料（过渡金属氧化物和有机物）进行系统研究，最终目标是建立一套标准的基准相关系统。