We present a twofold contribution to the numerical simulation of Lindblad equations. First, an adaptive numerical approach to approximate Lindblad equations using low-rank dynamics is described: a deterministic low-rank approximation of the density operator is computed, and its rank is adjusted dynamically, using an on-the-fly estimator of the error committed when reducing the dimension. On the other hand, when the intrinsic dimension of the Lindblad equation is too high to allow for such a deterministic approximation, we combine classical ensemble averages of quantum Monte Carlo trajectories and a denoising technique. Specifically, a variance reduction method based upon the consideration of a low-rank dynamics as a control variate is developed. Numerical tests for quantum collapse and revivals show the efficiency of each approach, along with the complementarity of the two approaches.
Restricted Monte Carlo wave function method and Lindblad equation for identifying entangling open-quantum-system dynamics
Institute for Photonic Quantum Systems (PhoQS), Paderborn University（光子量子系统研究所（PhoQS），帕德博恩大学）；Niels Bohr Institute, University of Copenhagen（尼尔斯·玻尔研究所，哥本哈根大学）
Dissipative ground state preparation in ab initio electronic structure theory
Tsinghua University（清华大学）；University of California, Berkeley（加州大学伯克利分校）；California Institute of Technology（加州理工学院）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
Path-Integral Formulation of Bosonic Markovian Open Quantum Dynamics with Monte Carlo stochastic trajectories using the Glauber-Sudarshan P, Wigner, and Husimi Q Functions and Hybrids
Nagoya University（名古屋大学）；Institute of Science Tokyo（东京科学大学）
