Enhanced Tuneable Rotatory Power in a Rotating Plasma

TL;DR

This paper analytically explores the gyrotropic properties of rotating plasmas, revealing a significant enhancement in polarization rotation due to polarization drag, with potential applications in non-reciprocal devices and THz gyrotropy.

Contribution

It introduces the first analytical demonstration of giant polarization drag in rotating plasmas, surpassing Faraday rotation by four orders of magnitude at GHz frequencies.

Findings

Polarization drag can be $10^4$ larger than Faraday rotation.

Rotation induces a new cutoff for wave propagation along magnetic fields.

Potential for unprecedented gyrotropy in the THz regime.

Abstract

The gyrotropic properties of a rotating magnetized plasma are derived analytically. Mechanical rotation leads to a new cutoff for wave propagation along the magnetic field and polarization rotation above this cutoff is the sum of the classical magneto-optical Faraday effect and the mechanico-optical polarization drag. Exploiting the very large effective group index near the cutoff, we expose here, for the first time, that polarization drag can be $10^4$ larger than Faraday rotation at GHz frequency. The rotation leads to weak absorption while allowing direct frequency control, demonstrating the unique potential of rotating plasmas for non-reciprocal elements. The very large rotation frequency of a dense non-neutral plasma could enable unprecedented gyrotropy in the THz regime.