Continuum damping of topologically-protected edge modes at the boundary of non-uniformly magnetized cylindrical plasmas

Abstract: We present an extension of recently discovered collisionlessly damped yet topologically protected surface plasma waves (TSPWs), from a simplified slab geometry to a cylindrical plasma-vacuum interface. A distinctive feature of these modes-emerging above the electron cyclotron frequency-is their collisionless damping, which arises from resonant coupling to a continuum of upper-hybrid modes localized within a smooth plasma-vacuum transition layer. We demonstrate both temporal and spatial damping of TSPWs at the boundary of a cylindrical magnetized plasma. Furthermore, we show that in the presence of a non-uniform magnetic field, the TSPW exhibits a smooth and continuous transition, highlighting its topological robustness under magnetic inhomogeneity.