Electron Dynamics in Open Quantum Systems: The Driven Liouville-von Neumann Methodology within Time-Dependent Density...

Area of Science:

• Quantum Mechanics
• Computational Physics
• Materials Science

Background:

• Understanding electron dynamics in open quantum systems is crucial for designing novel electronic devices.
• Simulating systems driven far from equilibrium presents significant computational challenges.
• Existing methods often struggle to accurately capture non-equilibrium electron behavior.

Purpose of the Study:

• To develop a first-principles computational approach for describing electron dynamics in open quantum systems under external time-dependent stimuli.
• To validate the new methodology by applying it to model systems and comparing results with established methods.
• To demonstrate the capability of the approach for analyzing non-equilibrium dynamics and current densities.

Main Methods:

• Utilizing the driven Liouville-von Neumann methodology to incorporate open boundary conditions.
• Employing time-dependent density functional theory (TD-DFT) to describe system dynamics.
• Applying the method to spin-compensated model systems like hydrogen chains and graphitic molecular junctions.

Main Results:

• The computational approach successfully describes electron dynamics in open quantum systems.
• Validated by good agreement between direct propagation and Sylvester equation solutions for steady-state currents.
• Demonstrated capability to analyze non-equilibrium dynamics via temporally and spatially resolved current densities.

Conclusions:

• The developed first-principles method provides a robust framework for studying electron dynamics in driven open quantum systems.
• The approach is validated and capable of analyzing complex non-equilibrium phenomena.
• Future work will extend the methodology to include dynamical magnetization and decoherence effects.