Magnetoelectric Resonances and Predicted Microwave Diode Effect of Skyrmion Crystal in Multiferroic Chiral-Lattice Magnet

TL;DR

This paper theoretically demonstrates that skyrmion crystals in a multiferroic magnet exhibit coupled electric and magnetic resonances, leading to a large microwave diode effect with potential device applications.

Contribution

It reveals the magnetoelectric resonances of skyrmion crystals and predicts a significant microwave diode effect in multiferroic chiral magnets.

Findings

Skyrmion eigenmodes are active to both magnetic and electric fields.

Interference between electric and magnetic activation causes large diode effect.

Microwave absorption difference can reach up to 20% based on incident direction.

Abstract

We theoretically discover that unique eigenmodes of skyrmion crystal (SkX) are not only magnetically active to ac magnetic field (H^w) but also electrically active to ac electric field (E^w) in a multiferroic chiral-lattice magnet Cu2OSeO3, which amplifies the dynamical magnetoelectric coupling between E^w and the spin texture. The resulting intense interference between their electric and magnetic activation processes can lead to unprecedentedly large diode effect on the microwave, i.e., its absorption by SkX changes up to ~20% when the incident direction is reversed. Our results demonstrate that the skyrmion can be a promising building block for microwave devices.