Giant Real-time Strain-Induced Anisotropy Field Tuning in Suspended Yttrium Iron Garnet Thin Films

TL;DR

This paper demonstrates a novel suspended YIG thin-film resonator that achieves giant, real-time strain-induced frequency tuning, significantly surpassing previous limits and enabling energy-efficient on-chip microwave and spintronic devices.

Contribution

It introduces a heterogenous YIG-on-Si resonator with a suspended structure that allows large, real-time strain tuning of magnetism and frequency, a breakthrough in YIG device control.

Findings

Achieved 1.837 GHz strain tuning in YIG resonators.

Demonstrated up to 1.06% strain in YIG thin-films.

Realized a magnetocrystalline anisotropy field of 642 Oe.

Abstract

Yttrium Iron Garnet based tunable magnetostatic wave and spin wave devices are poised to revolutionize the fields of Magnonics, Spintronics, Microwave devices, and quantum information science. The magnetic bias required for operating and tuning these devices is traditionally achieved through large power-hungry electromagnets, which significantly restraints the integration scalability, energy efficiency and individual resonator addressability. While controlling the magnetism of YIG mediated through its magnetostrictive/magnetoelastic interaction would address this constraint and enable novel strain/stress coupled magnetostatic wave (MSW) and spin wave (SW) devices, effective real-time strain-induced magnetism change in YIG remains elusive due to its weak magnetoelastic coupling efficiency and substrate clamping effect. We demonstrate a heterogeneous YIG-on-Si MSW resonator with a suspended thin-film device structure, which allows significant straining of YIG to generate giant magnetism change in YIG. By straining the YIG thin-film in real-time up to 1.06%, we show, for the first time, a 1.837 GHz frequency-strain tuning in MSW/SW resonators, which is equivalent to an effective strain-induced magnetocrystalline anisotropy field of 642 Oe. This is significantly higher than the previous state-of-the-art of 0.27 GHz of strain tuning in YIG. The unprecedented strain tunability of these YIG resonators paves the way for novel energy-efficient integrated on-chip solutions for tunable microwave, photonic, magnonic, and spintronic devices.