Generalized Quantum Master Equation from Memory Kernel Coupling Theory

Area of Science:

• Quantum Physics
• Computational Chemistry
• Materials Science

Background:

• The generalized quantum master equation is crucial for modeling non-Markovian dynamics in open quantum systems.
• Accurate and efficient computation of the memory kernel is a significant challenge in these models.

Purpose of the Study:

• To introduce a tensorial extension of the memory kernel coupling theory (MKCT) to address the computational bottlenecks in evaluating memory kernels.
• To enable the calculation of general expectation values and cross-correlation functions within this extended framework.

Main Methods:

• Developed a comprehensive tensorial extension of the memory kernel coupling theory (MKCT).
• Elevated the original scalar formalism to a tensorial framework for enhanced computational capabilities.
• Applied the extended MKCT to benchmark systems including the spin-boson model, Fenna-Matthews-Olson complex, and 1D lattice models.

Main Results:

• Demonstrated the numerical accuracy and efficiency of the tensorial MKCT.
• Successfully captured transient populations and coherences in the spin-boson model.
• Accurately resolved the excitonic absorption spectrum of the Fenna-Matthews-Olson complex.
• Simulated charge mobility in one-dimensional lattice models with high fidelity.

Conclusions:

• The tensorial MKCT provides a highly efficient and accurate method for investigating complex dynamics in open quantum systems.
• This advancement overcomes previous limitations in memory kernel evaluation, paving the way for more sophisticated quantum system simulations.