Improved Green’s function measurement for hybridization expansion quantum Monte Carlo

Abstract

We present an algorithm for measurement of the Green’s function in the hybridization expansion continuous-time quantum Monte-Carlo method based on continuous estimators. Compared to the standard method, the present algorithm has a similar or better accuracy with an improvement notable especially at low perturbation orders and high frequencies. The resulting statistical noise is weakly correlated so high-accuracy data for the numerical analytical continuation can be produced.