Perturbation expansions of stochastic wavefunctions for open quantum systems

作者：Ke, Yaling; Zhao, Yi^*

来源：Journal of Chemical Physics, 2017, 147(18): 184103.

DOI：10.1063/1.4996737

• SPIN-BOSON MODEL
• EXCITATION-ENERGY TRANSFER
• REDUCED DENSITY-MATRICES
• MASTER EQUATION
• STATE DIFFUSION
• TIME EVOLUTION
• STRUCTURED ENVIRONMENT
• SCHRODINGER-EQUATION
• TENSOR PROPAGATOR
• NOISE BATH

Based on the stochastic unravelling of the reduced density operator in the Feynman path integral formalism for an open quantum system in touch with harmonic environments, a new non-Markovian stochastic Schrodinger equation (NMSSE) has been established that allows for the systematic perturbation expansion in the system-bath coupling to arbitrary order. This NMSSE can be transformed in a facile manner into the other two NMSSEs, i.e., non-Markovian quantum state diffusion and time-dependent wavepacket diffusion method. Benchmarked by numerically exact results, we have conducted a comparative study of the proposed method in its lowest order approximation, with perturbative quantum master equations in the symmetric spin-boson model and the realistic Fenna-Matthews-Olson complex. It is found that our method outperforms the second-order time-convolutionless quantum master equation in the whole parameter regime and even far better than the fourth-order in the slow bath and high temperature cases. Besides, the method is applicable on an equal footing for any kind of spectral density function and is expected to be a powerful tool to explore the quantum dynamics of large-scale systems, benefiting from the wavefunction framework and the time-local appearance within a single stochastic trajectory. Published by AIP Publishing.

• 出版日期2017-11-14
• 单位厦门大学