# A magnetic monopole nanoantenna

## TL;DR

This paper introduces a novel photonic nanoantenna that mimics magnetic monopole behavior, enabling enhanced magnetic field radiation at the nanoscale, with potential applications in magnetic light studies and imaging.

## Contribution

It proposes a new nanoantenna design using a half-nanoslit in gold to generate a radiating magnetic monopole-like field, a concept not previously demonstrated.

## Key findings

- The nanoantenna produces a single magnetic pole with enhanced magnetic fields.
- It radiates efficiently in the far field, demonstrating monopole-like behavior.
- Potential applications include magnetic light research and magnetic resonance imaging.

## Abstract

Magnetic monopoles are hypothetical particles that, like electric monopoles which generate electric fields, are at the origin of magnetic fields. Despite many efforts, to date, these theoretical particles have yet to be observed. Nevertheless, many systems or physical phenomena can be related to magnetic monopole behavior. Here, we propose a new type of photonic nanoantenna behaving as a radiating magnetic monopole. We demonstrate that a half-nanoslit in a semi-infinite gold layer generates a single pole of an enhanced magnetic field at the nanoscale and that this single pole radiates efficiently in the far field. This original antenna concept opens the way to a new model system to study magnetic monopoles, to a new source of optical magnetic field to study the "magnetic light" and matter coupling, and allows potential applications at other frequencies such as magnetic resonance imaging.

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Source: https://tomesphere.com/paper/2302.13297