Electrical excitation of shock and soliton-like waves in two-dimensional electron channels

TL;DR

This paper investigates the formation and propagation of nonlinear plasma waves, including shock and soliton-like waves, in two-dimensional electron channels using hydrodynamic models with self-consistent electric potential.

Contribution

It introduces a detailed hydrodynamic model accounting for viscosity and collisions to analyze nonlinear wave formation in 2D electron channels, highlighting factors affecting wave shape and damping.

Findings

Shock and soliton-like waves form from nonuniform electron densities.

Viscosity and channel parameters influence wave shape and damping.

Collisions damp waves without significantly changing shock front thickness.

Abstract

We study electrical excitation of nonlinear plasma waves in heterostructures with two-dimensional electron channels and with split gates, and the propagation of these waves using hydrodynamic equations for electron transport coupled with two-dimensional Poisson equation for self-consistent electric potential. The term related to electron collisions with impurities and phonons as well as the term associated with viscosity are included into the hydrodynamic equations. We demonstrate the formation of shock and soliton-like waves as a result of the evolution of strongly nonuniform initial electron density distribution. It is shown that the shock wave front and the shape of soliton-like pulses pronouncedly depend on the coefficient of viscosity, the thickness of the gate layer and the nonuniformity of the donor distribution along the channel. The electron collisions result in damping of the shock and soliton-like waves, while they do not markedly affect the thickness of the shock wave front.