2020/01/06 by Masafumi Fukuma, Nobuyuki Matsumoto, Fukuma, Masafumi +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #Quantum many-body systems #Statistical Mechanics (cond-mat.stat-mech) #Statistical Mechanics and Entropy #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.2001.01665
openalex publication_date 2020/01/06 · openalex created_date 2020/01/10 · openalex updated_date 2026/07/28
The tempered Lefschetz thimble method (TLTM) is a parallel-tempering algorithm towards solving the numerical sign problem. It tames both the sign and ergodicity problems simultaneously by tempering the system with the flow time of continuous deformations of the integration region. In this article, after reviewing the basics of the TLTM, we explain a new algorithm within the TLTM that enables us to estimate the expectation values precisely with a criterion ensuring global equilibrium and the sufficiency of the sample size. To demonstrate the effectiveness of the algorithm, we apply the TLTM to the quantum Monte Carlo simulation of the Hubbard model away from half filling on a two-dimensional lattice of small size, and show that the obtained numerical results agree nicely with exact values.