Boundary instability of a two-dimensional plasma

TL;DR

This paper extends previous one-dimensional plasma instability analysis to two dimensions, revealing boundary-localized plasma wave instabilities that could lead to turbulence in FETs with asymmetric boundaries.

Contribution

It introduces a two-dimensional analysis of plasma instabilities in FETs, identifying boundary-localized modes and their potential to cause turbulence, expanding understanding beyond prior one-dimensional models.

Findings

Instability modes are localized near boundaries and propagate perpendicular to current.

Predicted plasma turbulence with a broad frequency spectrum.

Similar boundary instabilities may occur in single boundary FET structures.

Abstract

It was shown previously that the current-carrying state of a Field Effect Transistor with asymmetric source and drain boundary conditions may become unstable against spontaneous generation of plasma waves [1]. By extending the analysis to the two-dimensional case we find that the dominant instability modes correspond to waves propagating in the direction perpendicular to the current and localized near the boundaries. This new type of instability should result in plasma turbulency with a broad frequency spectrum. More generally, it is shown that a similar instability might exist, when a strong enough current goes through a single boundary between the gated and ungated regions.