Electromagnetic Nonreciprocity in a Magnetized Plasma Circulator

TL;DR

This paper demonstrates experimentally that a magnetized plasma can be used to create a microwave circulator with nonreciprocal wave transmission, showing potential for practical applications in topological electromagnetic systems.

Contribution

It provides the first experimental proof-of-concept of a plasma-based microwave circulator demonstrating nonreciprocity in the 4-6 GHz range.

Findings

Wide band isolation achieved in experiments

Performance tunable via plasma density and magnetic field

Simulation and experimental results are consistent

Abstract

Nonreciprocal transport of electromagnetic waves within magnetized plasma is a powerful building block towards understanding and exploiting the properties of more general topological systems. Much recent attention has been paid to the theoretical issues of wave interaction within such a medium, but there is a lack of experimental verification that such systems can be viable in a lab or industrial setting. This work provides an experimental proof-of-concept by demonstrating nonreciprocity in a unit component, a microwave plasma circulator. We design an E-plane Y junction plasma circulator operating in the range of 4 to 6 GHz using standardized waveguide specifications. From both simulations and experiments, we observe wide band isolation for the power transmission through the circulator. The performance and the frequency band of the circulator can be easily tuned by changing the plasma density and the magnetic field strength. By linking simulations and experimental results, we estimate the plasma density for the device.