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DOE OSTI · 21408691

Algorithm for simulation of quantum many-body dynamics using dynamical coarse-graining

Khasin, M·Kosloff, R
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Abstract

An algorithm for simulation of quantum many-body dynamics having su(2) spectrum-generating algebra is developed. The algorithm is based on the idea of dynamical coarse-graining. The original unitary dynamics of the target observables--the elements of the spectrum-generating algebra--is simulated by a surrogate open-system dynamics, which can be interpreted as weak measurement of the target observables, performed on the evolving system. The open-system state can be represented by a mixture of pure states, localized in the phase space. The localization reduces the scaling of the computational resources with the Hilbert-space dimension n by factor n{sup 3/2}(ln n){sup -1} compared to conventional sparse-matrix methods. The guidelines for the choice of parameters for the simulation are presented and the scaling of the computational resources with the Hilbert-space dimension of the system is estimated. The algorithm is applied to the simulation of the dynamics of systems of 2x10{sup 4} and 2x10{sup 6} cold atoms in a double-well trap, described by the two-site Bose-Hubbard model.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICSALGEBRAALGORITHMSBANACH SPACECHARGED PARTICLESCRYSTAL MODELSHILBERT SPACEHUBBARD MODELIONSMANY-BODY PROBLEMMATHEMATICAL LOGICMATHEMATICAL MODELSMATHEMATICAL SPACEMATHEMATICSNITROGEN IONSPHASE SPACERESOURCESSIMULATIONSPACESPECTRA

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Khasin, M, Kosloff, R. 2010-04-15. Algorithm for simulation of quantum many-body dynamics using dynamical coarse-graining. https://doi.org/10.1103/physreva.81.043635

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