Tunneling dynamics with a mixed quantum-classical method: quantum corrected propagator combined with frozen Gaussian...

Area of Science:

• Quantum mechanics
• Chemical physics
• Computational chemistry

Background:

• Mixed quantum-classical (MQC) methods are crucial for simulating systems with distinct quantum and classical behaviors.
• Treating tunneling effects in multidimensional systems remains a significant computational challenge.

Purpose of the Study:

• To extend the recently developed MQC propagation method to incorporate tunneling effects in multidimensional systems.
• To accurately simulate the dynamics of quantum subsystems interacting with classical environments.

Main Methods:

• The study employs a frozen Gaussian description for the classical bath degrees of freedom.
• Quantum subsystem dynamics are governed by a corrected propagator derived from zeroth-order propagator matrix elements.
• The method is applied to a model system: a double-well potential coupled to a harmonic oscillator.

Main Results:

• The extended MQC method successfully treats tunneling effects in multidimensional systems.
• Inclusion of nondiagonal elements in the correction propagator enables accurate tunneling treatment.
• Accurate simulation of tunneling in an antisymmetric double-well potential was achieved.

Conclusions:

• The developed MQC propagation method provides an accurate and efficient way to study tunneling in complex systems.
• This advancement is significant for computational chemistry and quantum dynamics simulations.
• The method's ability to handle multidimensional tunneling opens new avenues for theoretical research.