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

作者：Khasin M^*; Kosloff R

来源：Physical Review A, 2010, 81(4): 043635.

DOI：10.1103/PhysRevA.81.043635

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(3/2)(ln n)(-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 2 x 10(4) and 2 x 10(6) cold atoms in a double-well trap, described by the two-site Bose-Hubbard model.

• 出版日期2010-4