Propagation and collisionless damping of topologically-protected surface plasma waves in non-uniformly magnetized plasma columns

TL;DR

This paper extends the theory of topologically-protected surface plasma waves (TSPWs) to realistic 3D magnetic fields, demonstrating their minimal reflection and localized damping in non-uniform magnetized plasma columns, which is promising for plasma wave applications.

Contribution

It advances the understanding of TSPWs by analyzing their behavior in realistic 3D magnetic field configurations, highlighting their low reflection and localized damping properties.

Findings

TSPWs can propagate with negligible reflection in non-uniform magnetic fields.

Collisionless damping occurs in localized regions as TSPWs move away from magnetic coils.

TSPWs maintain reflectionless propagation even in complex 3D magnetic geometries.

Abstract

Recent theoretical studies revealed the existence of topologically-protected surface plasma waves (TSPWs) in cold magnetized plasmas assumed uniform along the direction of a uniaxial magnetic field. Reflections-free propagation of the TSPWs along arbitrarily-shaped plasma boundaries oriented perpendicularly to the magnetic field was shown to be preserved even when their collisionless damping by localized upper-hybrid resonances was accounted for. Here we extend this theory to the realistic case of three-dimensional magnetic field produced by finite-sized magnetic coils. We demonstrate that when TSPWs are launched in the direction of the decreasing magnetic field, they are collisionlessly absorbed within a highly localized (evanescent) region as they propagate away from the magnetic coil. We show that the resulting wave reflection can be negligible -- in clear contrast with conventional wave reflection from the corresponding evanescence regions.