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Related Experiment Video

Updated: May 19, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

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Published on: December 4, 2017

Exact density-functional potentials for time-dependent quasiparticles.

J D Ramsden¹, R W Godby

¹Department of Physics, University of York and European Theoretical Spectroscopy Facility (ETSF), Heslington, York YO10 5DD, United Kingdom.

Physical Review Letters

|August 7, 2012

Summary

This summary is machine-generated.

We calculated the exact Kohn-Sham potential for electron wave packets in semiconductors. This potential shows nonlocal dependencies on charge density, unlike simpler approximations.

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Area of Science:

Condensed matter physics
Quantum mechanics
Computational materials science

Background:

Time-dependent density-functional theory (TDDFT) is crucial for describing electron dynamics.
Accurate Kohn-Sham potentials are essential for reliable TDDFT calculations.
Existing approximations may not fully capture complex electron behavior.

Purpose of the Study:

To determine the exact Kohn-Sham potential for electron quasiparticle wave packet propagation.
To investigate the functional dependence of this potential on charge density.
To identify key components for accurate nonequilibrium TDDFT.

Main Methods:

Calculation of the exact Kohn-Sham potential within TDDFT.
Simulation of an electron quasiparticle wave packet with nonzero crystal momentum.
Analysis of the potential's dependence on charge density in space and time.

Main Results:

The exact Kohn-Sham potential exhibits strong nonlocal functional dependence on charge density.
This nonlocal behavior is absent in local and adiabatic approximations.
The nonequilibrium electric field depends crucially on local current and charge density.

Conclusions:

The exact Kohn-Sham potential is highly nonlocal in both space and time.
Nonlocal dependencies are critical for accurately describing electron dynamics.
The identified dependence on local current and charge density is key for improved TDDFT functionals.