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arXiv · 2610.17979

Field-free Magnetoacoustic Nonreciprocity via Exchange-bias Engineering

Weiqi Du·Mingyuan Ma·Zheng Sun·Chong Chen·Shixuan Liang·Deqi Tao·Shihai An·Yifan Fu·Sulei Fu·Feng Pan·Cheng Song
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Abstract

Nonreciprocal wave propagation is essential for directional signal processing and isolation. Magnetoacoustic systems are attractive platforms for nonreciprocal devices because of their small footprint and passive operation. However, pronounced nonreciprocity typically requires an external bias field,limiting device miniaturization and integration. Here, we demonstrate field-free magnetoacoustic nonreciprocity in an IrMn/FeGaB/Cu/FeGaB multilayer integrated with a shear-horizontal-wave delay line. Exchange-bias engineering stabilizes a remanent magnetic state with broken time-reversal and spatial-inversion symmetries while tailoring the spin-wave dispersion to achieve resonant magnetoacoustic coupling at zero field. The normalized isolation reaches 21 dB/mm, with its sign programmable by the field-sweep history. Further numerical optimization predicts a zero-field normalized isolation of 91 dB/mm by increasing the dynamical magnetic asymmetry. Our work establishes exchange-bias engineering as a promising route toward compact RF isolators and circulators and as a general strategy for realizing magnetoacoustic devices without external magnetic fields.

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Weiqi Du, Mingyuan Ma, Zheng Sun, Chong Chen, Shixuan Liang, Deqi Tao, Shihai An, Yifan Fu, Sulei Fu, Feng Pan, Cheng Song. 2026-10-13. Field-free Magnetoacoustic Nonreciprocity via Exchange-bias Engineering. https://arxiv.org/abs/2610.17979

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