Deep sub-wavelength scale focusing of heat flux radiated by magneto-optical nanoemitters in the presence of an external magnetic-field

TL;DR

This paper presents a theoretical framework for controlling heat flux at the nanoscale using magneto-optical emitters and external magnetic fields, enabling focused heat transfer for advanced magnetic recording.

Contribution

It introduces a novel theoretical model for near-field heat transfer involving magneto-optical nanoemitters under magnetic fields, demonstrating sub-wavelength heat focusing effects.

Findings

External magnetic field amplifies heat exchange.

Magnetic field induces sub-wavelength heat focusing.

Potential applications in heat-assisted magnetic recording.

Abstract

We introduce a theoretical framework to describe the heat flux radiated in the near-field regime by a set of magneto-optical thermal nanoemitters close to a substrate in the presence of an external magnetic field. Then, we investigate the particular case of a single emitter and we demonstrate that the external field can induce both an amplification of the heat exchanged between emittter and substrate and a focusing of the Poynting field at the substrate interface at deep sub-wavelength scale. These effects open up promising perspectives for the development of heat-assisted magnetic-recording technology.