Open quantum dynamics with variational non-Gaussian states and the truncated Wigner approximation.

Area of Science:

• Quantum Physics
• Computational Chemistry
• Condensed Matter Physics

Background:

• Simulating open quantum systems, particularly spin-boson models, is crucial for understanding phenomena in quantum chemistry and condensed matter.
• Existing methods face challenges in accurately capturing the complex dynamics of these systems.

Purpose of the Study:

• To introduce a novel computational framework for simulating the open dynamics of spin-boson systems.
• To apply and benchmark this framework against the truncated Wigner approximation for a versatile spin-boson Hamiltonian.

Main Methods:

• A hybrid approach combining variational non-Gaussian states with a quantum trajectories method.
• Application to a generic spin-boson Hamiltonian featuring Tavis-Cummings and Holstein couplings.
• Benchmarking against the truncated Wigner approximation for open quantum systems.

Main Results:

• The proposed framework accurately simulates the open dynamics of spin-boson systems.
• Identified specific regimes where the variational non-Gaussian states and truncated Wigner approximation methods are most effective.
• Provided a comparative analysis of the strengths and weaknesses of both simulation techniques.

Conclusions:

• The developed framework offers a powerful tool for studying open quantum system dynamics.
• The study elucidates the applicability and limitations of different simulation methods for spin-boson models.
• Strategies for enhancing both simulation techniques are discussed for future research.