Global Flux Surface Hopping Approach for Mixed Quantum-Classical Dynamics.

Area of Science:

• Quantum mechanics
• Computational chemistry
• Materials science

Background:

• Standard fewest switches surface hopping (FSSH) is a common method for simulating quantum dynamics.
• FSSH has limitations in accurately capturing certain population transfer mechanisms, such as superexchange.

Purpose of the Study:

• To introduce a novel global flux surface hopping (GFSH) approach.
• To address the limitations of FSSH in modeling complex population transfer dynamics.

Main Methods:

• Developed GFSH, where surface hopping probabilities are based on gross population flow between states.
• Compared GFSH to FSSH in terms of population transfer, hop minimization, internal consistency, and detailed balance.
• Applied GFSH to a model 3-level system and an Auger process in a semiconductor quantum dot.

Main Results:

• GFSH successfully captures the superexchange mechanism, which FSSH cannot.
• GFSH demonstrates advantages in population transfer accuracy.
• GFSH maintains similarities to FSSH in other aspects like hop minimization and internal consistency.

Conclusions:

• The novel GFSH approach offers a promising alternative to FSSH for quantum dynamics simulations.
• GFSH's ability to model superexchange is a significant advancement.
• Further validation studies are recommended to fully establish GFSH as a replacement for FSSH.