Finite-temperature Quantum Monte Carlo algorithms for correlated fermion systems:developments and applications
报告题目: Finite-temperature Quantum Monte Carlo algorithms for correlated fermion systems:developments and applications
报告人:何院耀 博士, Flatiron Research Fellow
Center for Computational Quantum Physics, Flatiron Institute
In this talk, I will introduce our most recent developments of finite-temperature Quantum Monte Carlo (QMC) methods for correlated fermion systems and the ongoing applications. The talk will be divided into two parts. In the first part, I will present the finite-temperature constrained-path QMC method which is used to control the sign problem, as well as its application for studying the stripe phase in 2D doped Hubbard model with repulsive interactions. In the second part, I will talk about our very recent, great progress on general finite-temperature QMC methods, in which we reduce the computational cost from the cubic scaling of number of lattice sites (or basis size) to linear. This new algorithm can speed up the simulations by orders of magnitudes, and it allows forab initioQMC simulations at finite temperatures for various fermion systems, ranging from lattice models to fermi gases, Quantum chemistry and real materials. I will also show some preliminary results for 2D spin-balanced fermi gas with zero-range attractive interaction.
Yuan-Yao He got his PhD of Physics in Department of Physics, Renmin University of China in June 2018. In Sept. 2018, he moved to Center for Computational Quantum Physics (CCQ), Flatiron Institute (which is a division of Simons Foundation) in New York as a Flatiron Research Fellow. During his PhD, he focused on studying interacting topological insulators in lattice models using various quantum many-body numerical techniques, such as Exact Diagonalizations (ED) and Quantum Monte Carlo (QMC) methods. Since then, he mainly works on the developments and applications of finite-temperature QMC algorithms for correlated fermion systems, including the determinantal QMC method and the constrained-path QMC method which is used to control the sign problem. Most recently, he and his collaborators have dramatically reduced the computational cost of finite-temperature QMC methods by orders of magnitudes. This newest development allows forab initioQMC simulations at finite temperatures for various fermion systems, ranging from lattice models to fermi gases, Quantum chemistry and real materials.