In this work we introduce a modified real-time continuous-time hybridization-expansion quantum Monte Carlo solver for a time-dependent single-orbital Anderson impurity model: CT-1/2-HYB-QMC. In the proposed method the diagrammatic expansion is performed only for one out of the two spin channels, while the resulting effective single-particle problem for the other spin is solved semi-analytically for each expansion diagram. CT-1/2-HYB-QMC alleviates the dynamical sign problem by reducing the order of sampled diagrams and makes it possible to reach twice as long time scales in comparison to the standard CT-HYB method. We illustrate the new solver by calculating an electric current through impurity in paramagnetic and spin-polarized cases.
@article{arxiv.1904.12582,
title = {Exact real-time dynamics of single-impurity Anderson model from a single-spin hybridization-expansion},
author = {Patryk Kubiczek and Alexey N. Rubtsov and Alexander I. Lichtenstein},
journal= {arXiv preprint arXiv:1904.12582},
year = {2019}
}