title: Wang-Landau method for calculating Rényi entropies in finite-temperature quantum Monte Carlo simulations.
abstract: We implement a Wang-Landau sampling technique in quantum Monte Carlo (QMC) simulations for the purpose of calculating the Rényi entanglement entropies and associated mutual information. The algorithm converges an estimate for an analog to the density of states for stochastic series expansion QMC, allowing a direct calculation of Rényi entropies without explicit thermodynamic integration. We benchmark results for the mutual information on two-dimensional (2D) isotropic and anisotropic Heisenberg models, a 2D transverse field Ising model, and a three-dimensional Heisenberg model, confirming a critical scaling of the mutual information in cases with a finite-temperature transition. We discuss the benefits and limitations of broad sampling techniques compared to standard importance sampling methods.
authors: Department of Physics and Astronomy, University of Waterloo, 200 University Avenue, Ontario, Canada, N2L 3G1. dartonias@gmail.com
authors: Stephen
authors: S
authors: Inglis
authors: Roger G
authors: RG
authors: Melko
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D019277:Entropy; D015233:Models, Statistical; D009010:Monte Carlo Method; D009716:Numerical Analysis, Computer-Assisted; D011789:Quantum Theory; D013696:Temperature; D013816:Thermodynamics