Nonadiabatic Dynamics in Single-Electron Tunneling Devices with Time-Dependent Density-Functional Theory

Area of Science:

• Condensed Matter Physics
• Quantum Transport
• Computational Many-Body Physics

Background:

• Simulating electron dynamics in quantum systems is crucial for developing novel electronic devices.
• Accurate modeling of quantum dots requires accounting for electron-electron interactions and quantum tunneling.

Purpose of the Study:

• To develop a time-dependent density-functional theory (TDDFT) approach for simulating single-electron sources.
• To introduce a time-nonlocal exchange-correlation potential applicable to quantum transport.

Main Methods:

• Utilizing time-dependent density-functional theory (TDDFT) to model a quantum dot connected to a lead.
• Developing a time-nonlocal exchange-correlation potential inspired by quantum transport theory.
• Analyzing the emergence of a dynamical potential step and its relation to relaxation timescales.

Main Results:

• Successfully simulated the dynamics of a single-electron source with Coulomb interaction and tunnel coupling.
• Introduced a novel time-nonlocal potential that exhibits a dynamical step.
• Established a direct link between the time evolution of this step and electron relaxation dynamics.

Conclusions:

• The developed TDDFT method provides a robust framework for studying electron dynamics in mesoscopic systems.
• The time-nonlocal potential offers a promising avenue for more accurate simulations of quantum transport phenomena.
• Future work can extend this approach to larger and more complex mesoscopic systems.