Hybrid structure with a ferromagnetic film and an array of magnetic molecules for deep-nanoscale reprogrammable magnonics

TL;DR

This paper introduces a novel hybrid ferromagnetic and magnetic molecule structure that enables reprogrammable, deep-nanoscale magnonic devices with tunable frequency gaps, advancing spin-wave-based neuromorphic technologies.

Contribution

It proposes a new hybrid platform combining ferromagnetic films and magnetic molecules, demonstrating controllable spin-wave gaps for deep-nanoscale magnonic applications.

Findings

Resonant coupling creates a tunable 150 MHz gap in spin-wave transmission.

External magnetic fields and molecular arrangements control the gap's properties.

The structure supports deep nanoscale reprogrammability for GHz-range applications.

Abstract

Miniaturization is an essential element in the development of information processing technologies and is also one of the main determinants of the usability of the tested artificial neural networks. It is also a key element and one of the main challenges in the development of magnonic neuromorphic systems. In this work, we propose a new platform for the development of these new spin-wave-based technologies. Using micromagnetic simulations, we demonstrate that magnetic molecules regularly arranged on the surface of a thin ferromagnetic layer enable resonant coupling of propagating spin waves with the dynamics of the molecules' magnetic moments, opening a gap in the transmission spectrum up to 150 MHz. The gap, its width, and frequency can be controlled by an external magnetic field or the arrangement of molecules on the ferromagnetic surface. Furthermore, the antiferromagnetic arrangement of the magnetic moments of molecules or clusters of molecules allows for control of the gap's position and width. Thus, the proposed hybrid structure offers reprogrammability and miniaturization down to the deep nanoscale, operating frequencies in the range of several GHz, key properties for the implementation of artificial neural networks.