2024/06/30 by André Erpenbeck, Thomas Blommel, Erpenbeck, Andre +9 · 6 citations
Chemical Engineering · Materials Science · Mathematics · Physics and Astronomy · #Advanced Chemical Physics Studies #Catalysis and Oxidation Reactions #Catalytic Processes in Materials Science #Computer science #Dynamic Monte Carlo method #Markov chain Monte Carlo #Mathematics #Monte Carlo method #Monte Carlo molecular modeling #Physics #Quantum #Quantum Monte Carlo #Quantum mechanics #Statistical physics #Statistics
paper · pdf · doi:10.48550/arxiv.2407.00771
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2024/06/30 · openalex created_date 2024/07/06 · openalex updated_date 2026/08/06
A precise dynamical characterization of quantum impurity models with multiple interacting orbitals is challenging. In quantum Monte Carlo methods, this is embodied by sign problems. A dynamical sign problem makes it exponentially difficult to simulate long times. A multi-orbital sign problem generally results in a prohibitive computational cost for systems with multiple impurity degrees of freedom even in static equilibrium calculations. Here, we present a numerically exact inchworm method that simultaneously alleviates both sign problems, enabling simulation of multi-orbital systems directly in the equilibrium or nonequilibrium steady-state. The method combines ideas from the recently developed steady-state inchworm Monte Carlo framework [Phys. Rev. Lett. 130, 186301 (2023)] with other ideas from the equilibrium multi-orbital inchworm algorithm [Phys. Rev. Lett. 124, 206405 (2020)]. We verify our method by comparison with analytical limits and numerical results from previous methods.