Public Research Seminar by Advanced Materials (AMAT) Thrust, HKUST(GZ) - The unified framework of Auxiliary-Field Quantum Monte Carlo methods for correlated fermion systems
Correlated fermion systems span a wide range—from lattice models and interacting Fermi gases to molecules and realistic electronic materials. Understanding their physical properties lies at the heart of modern condensed matter physics. In this talk, I will present a unified formalism based on finite-temperature Auxiliary-Field Quantum Monte Carlo (FT-AFQMC) method for simulating these diverse systems. Specifically, the Determinant Quantum Monte Carlo (DQMC) method provides numerically exact results in the absence of the sign problem, while the constrained-path Quantum Monte Carlo (CPQMC) approach effectively controls the sign problem and maintains high accuracy. I will highlight our recent advancements in FT-AFQMC, both in algorithmic development and physical applications. On the algorithmic side, we have introduced an accelerated implementation of FT-AFQMC and refined the constrained-path approximation. On the application side, I will focus on the 2D interacting Fermi gas, which has been studied extensively in ultracold atomic experiments. Our work investigates the BKT transition, key thermodynamic properties (including the equation of state and Tan’s contact), pseudogap phenomena, as well as the dynamic properties in bosonic channels.
何院耀，西北大学现代物理研究所教授、博士生导师。2013年6月，在南开大学凝聚态物理专业获理学学士学位，并入选国家首届“基础学科拔尖学生培养实验计划”；2018年6月在中国人民大学凝聚态物理专业获理学博士学位。2018年9月至2022年1月，在美国纽约Flatiron Institute，计算量子物理研究中心(CCQ)，任博士后研究员(Research Fellow)。2022年1月开始，在西北大学现代物理研究所工作，先后入选陕西省和国家青年人才项目。目前主要研究方向为凝聚态理论和强关联多体数值计算，包括量子蒙特卡洛算法的发展及其在格点模型、相互作用费米气体和关联电子材料等体系的应用，主要关注这些体系中量子磁性、超导超流性质、热力学和动力学性质的研究。目前已在Phy. Rev. Lett.，Phys. Rev. X和Phys. Rev. B等期刊发表学术论文30余篇，并在国内外学术会议上作邀请报告10余次，并多次在学术会议上讲授量子蒙特卡洛算法的教学报告。