k-Selective Electrical-to-Magnon Transduction with Realistic Field-distributed Nanoantennas

TL;DR

This paper develops a comprehensive framework combining electromagnetic simulations and micromagnetic modeling to accurately describe and optimize nanoantenna-driven spin wave excitation and detection in magnonic devices, validated by experiments.

Contribution

It introduces a realistic, simulation-based approach for analyzing and designing nanoantenna-based spin wave transducers, capturing complex field distributions and k-space filtering effects.

Findings

Quantitative agreement between simulations and experiments on YIG films.

Nanoantenna design acts as a tunable k-space filter for spin waves.

Provides design rules for low-power magnonic transducers.

Abstract

The excitation and detection of propagating spin waves with lithographed nanoantennas underpin both classical magnonic circuits and emerging quantum technologies. Here, we establish a framework for all-electrical propagating spin-wave spectroscopy (AEPSWS) that links realistic electromagnetic drive fields to micromagnetic dynamics. Using finite-element (FE) simulations, we compute the full vector near-field of electrical impedance-matched, tapered coplanar and stripline antennas and import this distribution into finite-difference (FD) micromagnetic solvers. This approach captures the antenna-limited wave-vector spectrum and the component-selective driving fields (perpendicular to the static magnetisation) that simplified uniform-field models cannot. From this coupling, we derive how realistic current return paths and tapering shapes, k-weighting functions, for Damon-Eshbach surface spin waves in yttrium-iron-garnet (YIG) films are, for millimetre-scale matched CPWs and linear tapers down to nanometre-scale antennas. Validation against experimental AEPSWS on a $48\,nm$ YIG film shows quantitative agreement in dispersion ridges, group velocities, and spectral peak positions, establishing that the antenna acts as a tunable k-space filter. These results provide actionable design rules for on-chip magnonic transducers, with immediate relevance for low-power operation regimes and prospective applications in quantum magnonics.