Current-dependent exchange-correlation potential for non-local absorption in quantum hydrodynamic theory

TL;DR

This paper introduces a current-dependent exchange-correlation potential within quantum hydrodynamic theory, enabling accurate, self-consistent modeling of collective excitations and plasmon dispersion in free electron gases.

Contribution

It develops a novel exchange-correlation potential that incorporates current dependence, improving the accuracy of quantum hydrodynamic models for electron gases.

Findings

Excellent agreement with full quantum calculations.

Enhanced modeling of broadening of collective excitations.

Improved correction to plasmon dispersion.

Abstract

The quantum hydrodynamic theory is a promising method for describing microscopic details of macroscopic systems. The hydrodynamic equation can be directly obtained from a single particle Kohn-Sham equation that includes the contribution of an external vector potential. This derivation allows to straightforwardly incorporate in the hydrodynamic equation an exchange-correlation viscoelastic term, so that broadening of collective excitation can be taken into account, as well as a correction to the plasmon dispersion. The result is an accurate self-consistent and computationally efficient hydrodynamic description of the free electron gas. A very accurate agreement with full quantum calculations is shown.