Impedance-controlled nonreciprocal surface waves at a magnetized plasma interface
Phys. Rev. Applied 25, 054012 – Published 5 May, 2026
DOI: https://doi.org/10.1103/wfhw-68nw
Abstract
Magnetized plasmas support nonreciprocal surface waves, but their operating frequency is typically set by the plasma density and magnetic bias. Here, nonreciprocal surface and leaky wave propagation at a magnetized plasma interface terminated by a high-impedance surface (HIS) is investigated. The dispersive surface impedance is treated as a boundary condition that directly modifies the surface wave dispersion. An analytical model predicts impedance-induced band splitting and additional nonreciprocal branches, enabling frequency-selective control of supported modes and their propagation direction. Full-wave simulations and microwave experiments using plasma columns validate the theory and demonstrate that tuning the HIS resonance shifts and reshapes the nonreciprocal bands without changing plasma parameters. The analysis of fields confirms unidirectional propagation and distinguishes confined surface modes from radiative leaky modes. The results establish impedance engineering as a simple and passive mechanism for frequency-agile nonreciprocity and provide a practical route toward compact isolators, circulators, and reconfigurable nonreciprocal microwave devices.
