Nonadiabatic Electron Dynamics in Tunneling Junctions: Lattice Exchange-Correlation Potential

Area of Science:

• Condensed Matter Physics
• Quantum Transport Theory
• Computational Materials Science

Background:

• Time-dependent density-functional theory (TDDFT) faces challenges in developing exchange-correlation functionals beyond the adiabatic approximation.
• Accurate modeling of quantum transport in mesoscopic systems requires advanced theoretical tools.

Purpose of the Study:

• To develop a nonadiabatic exchange-correlation functional for lattice models applicable to generic transport setups.
• To validate the functional against known results and analyze its behavior in specific systems.

Main Methods:

• Utilizing known theoretical results and exploiting symmetry properties of the system.
• Applying the functional to a single quantum dot connected to reservoirs.
• Analyzing the functional's performance in a linear chain model under bias voltage.

Main Results:

• The proposed functional reproduces established results for quantum dots.
• It correctly yields the adiabatic local-density approximation in the static limit.
• The functional accurately describes Coulomb blockade in a half-filled linear chain and reveals doping-dependent effects.

Conclusions:

• The developed nonadiabatic functional offers a promising advancement for TDDFT in quantum transport.
• It provides a more accurate description of electron dynamics and interactions in nanoscale devices.
• The findings pave the way for improved simulations of electronic transport phenomena.