Computing physical properties with quantum Monte Carlo methods with statistical fluctuations independent of system size

Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Dec;90(6):063317. doi: 10.1103/PhysRevE.90.063317. Epub 2014 Dec 24.

Abstract

We show that the recently proposed correlated sampling without reweighting procedure extends the locality (asymptotic independence of the system size) of a physical property to the statistical fluctuations of its estimator. This makes the approach potentially vastly more efficient for computing space-localized properties in large systems compared with standard correlated methods. A proof is given for a large collection of noninteracting fragments. Calculations on hydrogen chains suggest that this behavior holds not only for systems displaying short-range correlations, but also for systems with long-range correlations.