Quantum Quasi-Monte Carlo Technique for Many-Body Perturbative Expansions
ORAL
Abstract
High order perturbation theory has seen an unexpected recent revival for controlled calculations of quantum many-body systems, even at strong coupling. We adapt integration methods using low-discrepancy sequences to this problem. They greatly outperform state-of-the-art diagrammatic Monte Carlo simulations. In practical applications, we show speed-ups of several orders of magnitude with scaling as fast as 1/N in sample number N; parametrically faster than 1/N1/2 in Monte Carlo simulations. We illustrate our technique with a solution of the Kondo ridge in quantum dots, where it allows large parameter sweeps.
Finally, I will also present a recent extension of the technique to compute whole time-dependent Green functions via a kernel approach.
Finally, I will also present a recent extension of the technique to compute whole time-dependent Green functions via a kernel approach.
*The Flatiron Institute is a division of the Simons Foundation. X. W. and M. M. acknowledge funding from the French-Japanese ANR QCONTROL, E. U. FET UltraFastNano, and FLAG-ERA Gransport.
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Presenters
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Corentin Bertrand
- Simons Foundation
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA