Hydrodynamic model for relaxation of optically injected currents in quantum wells

TL;DR

This paper develops a hydrodynamic model to simulate the complex relaxation dynamics of optically injected currents in quantum wells, revealing sensitivity of electron density evolution to Coulomb interactions and nonlinear effects.

Contribution

It introduces a hydrodynamic approach combined with Hermite-Gaussian basis functions to analyze current relaxation in quantum wells, highlighting complex charge density patterns.

Findings

Charge and current densities exhibit complex patterns due to Coulomb and nonlinear effects.

The first moment of electron density is highly sensitive to the evolution dynamics.

The model captures picosecond-scale relaxation phenomena in quantum wells.

Abstract

We use a hydrodynamic model to describe the relaxation of optically injected currents in quantum wells on a picosecond time scale, numerically solving the continuity and velocity evolution equations with the Hermite-Gaussian functions employed as a basis. The interplay of the long-range Coulomb forces and nonlinearity in the equations of motion leads to rather complex patterns of the calculated charge and current densities. We find that the time dependence of even the first moment of the electron density is sensitive to this complex evolution.