Discretization of Structured Bosonic Environments at Finite Temperature by Interpolative Decomposition: Theory and...

Area of Science:

• Quantum Chemistry
• Computational Physics
• Spectroscopy

Background:

• Simulating open quantum systems requires accurate representation of bath spectral densities.
• Existing discretization methods can be computationally intensive and limited in scope.
• Understanding the dynamics of quantum systems interacting with environments is crucial in chemistry and physics.

Purpose of the Study:

• To introduce a novel, efficient method for discretizing the spectral density of bosonic heat baths.
• To reduce the degrees of freedom needed for simulating open quantum system dynamics.
• To provide a versatile approach applicable to various quantum systems and environments.

Main Methods:

• Leveraging low-rank decomposition of the Fourier-transform relation between bath correlation functions and spectral densities.
• Capturing time, frequency, and temperature dependencies within the spectral density-autocorrelation function.
• Combining the novel discretization with tensor-train formalism for complex non-Markovian environments.

Main Results:

• Significantly reduced degrees of freedom for open quantum system simulations.
• Demonstrated efficacy through benchmarking against existing methods.
• Successful application to simple models and a realistic electron transfer process in biological systems.
• Effective integration with tensor-train methods for complex environments.

Conclusions:

• The proposed spectral density discretization method offers a computationally efficient and versatile tool for quantum dynamics simulations.
• This approach enhances the study of open quantum systems, including those with non-Markovian characteristics.
• The findings provide a valuable perspective on selecting and applying spectral density discretization techniques in computational science.