Stochastic multi-configuration time-dependent Hartree for dissipative quantum dynamics with strong intramolecular...

Area of Science:

• Quantum dynamics
• Theoretical chemistry
• Statistical mechanics

Background:

• Dissipation dynamics are crucial for understanding open quantum systems.
• Existing methods struggle with strongly coupled multidimensional systems.
• Markovian bath interactions require accurate modeling.

Purpose of the Study:

• To explore dissipation dynamics in strongly coupled multidimensional systems.
• To develop and test new methods for thermalization in quantum systems.
• To accurately model systems with intramolecular coupling, Fermi resonances, and anharmonicity.

Main Methods:

• System-bath approach using stochastic multi-configuration time-dependent Hartree (sMCTDH) method.
• Development of novel Lindblad dissipative operators via unitary transformation to normal mode representation.
• Utilization of generalized raising/lowering operators to enforce Boltzmann distribution for thermalization.

Main Results:

• The sMCTDH method successfully thermalizes wave packets for weakly coupled systems.
• New Lindblad operators effectively reduce intermode coupling and achieve thermalization.
• The developed methods accurately model complex systems including Fermi resonances and anharmonicity.

Conclusions:

• The novel approach provides accurate simulation of dissipation dynamics in strongly coupled quantum systems.
• This work advances the theoretical framework for studying thermalization in complex molecular systems.
• The developed methods offer a robust tool for investigating quantum dynamics in condensed phases.