Tuning plasmonic cloaks with an external magnetic field

TL;DR

This paper introduces a method to actively tune plasmonic cloaks using an external magnetic field, enabling control over scattering properties and cloaking operation without changing physical parameters.

Contribution

It demonstrates how magnetic fields can reversibly switch and tune the cloaking effect in plasmonic devices using magneto-optical materials.

Findings

Magnetic fields can drastically reduce scattering cross-section.

Operation wavelength can be modified without changing material or geometry.

Cloak switching is reversible and robust to material losses.

Abstract

We propose a mechanism to actively tune the operation of plasmonic cloaks with an external magnetic field by investigating electromagnetic scattering by a dielectric cylinder coated with a magneto-optical shell. In the long wavelength limit we show that the presence of an external magnetic field may drastically reduce the scattering cross-section at all observation angles. We demonstrate that the application of external magnetic fields can modify the operation wavelength without the need of changing material and/or geometrical parameters. We also show that applied magnetic fields can reversibly switch on and off the cloak operation. These results, which could be achieved for existing magneto-optical materials, are shown to be robust to material losses, so that they may pave the way for developing actively tunable, versatile plasmonic cloaks.