Lanczos steps to improve variational wave functions

26th IUPAP Conference on Computational Physics

物理学;计算机科学

Becca, Federico^1 ; Hu, Wen-Jun^2 ; Iqbal, Yasir^3 ; Parola, Alberto^4 ; Poilblanc, Didier^5 ; Sorella, Sandro^1

Democritos National Simulation Center, Istituto Officina Dei Materiali Del CNR, SISSA-International School for Advanced Studies, Via Bonomea 265, Trieste

I-34136, Italy^1

Department of Physics and Astronomy, California State University, Northridge

CA

91330, United States^2

Institute for Theoretical Physics and Astrophysics, Julius-Maximilian's University of Würzburg, Am Hubland, Würzburg

D-97074, Germany^3

Dipartimento di Scienza e Alta Tecnologia, Universita dell'Insubria, Via Valleggio 11, Como

I-22100, Italy^4

Laboratoire de Physique Théorique, UMR-5152, CNRS, Université de Toulouse, Toulouse

F-31062, France^5

关键词: Exact results;    Frustrated Heisenberg model;    Heisenberg models;    Kagome lattice;    Large clusters;    Low-energy excitations;    Quantum Monte Carlo calculations;    Two-dimensional lattices;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/640/1/012039/pdf
DOI  :  10.1088/1742-6596/640/1/012039

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Gutzwiller-projected fermionic states can be efficiently implemented within quantum Monte Carlo calculations to define extremely accurate variational wave functions for Heisenberg models on frustrated two-dimensional lattices, not only for the ground state but also for low-energy excitations. The application of few Lanczos steps on top of these states further improves their accuracy, allowing calculations on large clusters. In addition, by computing both the energy and its variance, it is possible to obtain reliable estimations of exact results. Here, we report the cases of the frustrated Heisenberg models on square and Kagome lattices.