Accelerated impurity solver for DMFT and its diagrammatic extensions
| Autor: | Gabriel Kotliar, Andre-Marie Tremblay, Kwangmin Yu, Nicholas D'Imperio, Patrick Semon, Corey Melnick |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Strongly Correlated Electrons (cond-mat.str-el) Quantum Monte Carlo Monte Carlo method Hilbert space General Physics and Astronomy Creation and annihilation operators FOS: Physical sciences Observable Quantum number 01 natural sciences 010305 fluids & plasmas Condensed Matter - Strongly Correlated Electrons symbols.namesake Hardware and Architecture 0103 physical sciences symbols Statistical physics 010306 general physics Hamiltonian (quantum mechanics) Anderson impurity model |
| DOI: | 10.48550/arxiv.2010.08482 |
| Popis: | We present ComCTQMC, a GPU accelerated quantum impurity solver. It uses the continuous-time quantum Monte Carlo (CTQMC) algorithm wherein the partition function is expanded in terms of the hybridisation function (CT-HYB). ComCTQMC supports both partition and worm-space measurements, and it uses improved estimators and the reduced density matrix to improve observable measurements whenever possible. ComCTQMC efficiently measures all one and two-particle Green's functions, all static observables which commute with the local Hamiltonian, and the occupation of each impurity orbital. ComCTQMC can solve complex-valued impurities with crystal fields that are hybridized to both fermionic and bosonic baths. Most importantly, ComCTQMC utilizes graphical processing units (GPUs), if available, to dramatically accelerate the CTQMC algorithm when the Hilbert space is sufficiently large. We demonstrate acceleration by a factor of over 600 (100) in a simulation of $\delta$-Pu at 600 K with (without) crystal fields. In easier problems, the GPU offers less impressive acceleration or even decelerates the CTQMC. Here we describe the theory, algorithms, and structure used by ComCTQMC in order to achieve this set of features and level of acceleration. Comment: 49 pages, 19 figures, submitted to Computer Physics Communications |
| Databáze: | OpenAIRE |
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