Fast Green's Function Method for Ultrafast Electron-Boson Dynamics.

Area of Science:

• Condensed matter physics
• Quantum mechanics
• Materials science

Background:

• Electron-boson interactions govern ultrafast dynamics in molecules and solids.
• Time-resolved techniques probe these phenomena.
• Green's function methods are crucial for theoretical interpretation.

Purpose of the Study:

• To develop a computationally efficient real-time Green's function scheme.
• To address limitations of existing methods regarding computational cost and energy conservation.

Main Methods:

• A novel Green's function scheme with linear scaling in propagation time.
• Simultaneous dressing of electrons and bosons to ensure conservation laws.
• Real-time simulation of phonon-driven relaxation dynamics.

Main Results:

• The new method overcomes cubic scaling limitations, enabling longer simulations.
• Energy conservation is guaranteed by simultaneous electron and boson dressing.
• Nonthermal behavior of phonons was observed in an excited insulator.

Conclusions:

• The developed method offers a computationally efficient approach for electron-boson system simulations.
• Enables first-principles studies of systems with long propagation times.
• Provides insights into ultrafast dynamics and nonthermal phenomena.