Real-Time GW-Ehrenfest-Fan-Migdal Method for Nonequilibrium 2D Materials

Area of Science:

• Quantum chemistry and condensed matter physics.
• Materials science and nanotechnology.
• Computational physics and quantum many-body theory.

Background:

• Understanding photoexcited low-dimensional systems is key for advanced optoelectronics.
• Accurate first-principles predictions are hindered by complex light-matter, electron-electron, and electron-nuclear interactions.
• Existing methods struggle to simultaneously account for quantum coherence and non-Markovian effects.

Purpose of the Study:

• To develop and present an advanced ab initio many-body method for quantum simulations.
• To treat electrons and nuclei on equal footing, preserving fundamental conservation laws like total energy.
• To simulate the complex dynamics in photoexcited two-dimensional (2D) materials.

Main Methods:

• An advanced ab initio many-body method incorporating quantum coherence and non-Markovian effects.
• Simultaneous treatment of electrons and nuclei to conserve total energy.
• Real-time simulations of multivalley dynamics in molybdenum disulfide (MoS2) monolayer.

Main Results:

• A parameter-free description of the coherent-to-incoherent crossover in MoS2.
• Elucidation of microscopic and collective excitations' roles in dephasing and thermalization.
• Demonstration of the method's capability in complex quantum simulations.

Conclusions:

• The developed method offers a significant advancement for simulating photoexcited 2D materials.
• This provides crucial insights for functionalizing and integrating novel 2D materials in optoelectronics.
• The framework enables accurate, fundamental understanding of quantum dynamics in materials.