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arXiv · 2408.01160

Nanoscale spin rectifiers for harvesting ambient radiofrequency energy

Raghav Sharma·Tung Ngo·Eleonora Raimondo·Anna Giordano·Junta Igarashi·Butsurin Jinnai·Shishun Zhao·Jiayu Lei·Yong-Xin Guo·Giovanni Finocchio·Shunsuke Fukami·Hideo Ohno·Hyunsoo Yang
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Abstract

Radiofrequency harvesting using ambient wireless energy could be used to reduce the carbon footprint of electronic devices. However, ambient radiofrequency energy is weak (less than -20 dBm), and thermodynamic limits and high-frequency parasitic impedance restrict the performance of state-of-the-art radiofrequency rectifiers. Nanoscale spin rectifiers based on magnetic tunnel junctions have recently demonstrated high sensitivity, but suffer from a low a.c.-to-d.c. conversion efficiency (less than 1%). Here, we report a sensitive spin rectifier rectenna that can harvest ambient radiofrequency signals between -62 and -20 dBm. We also develop an on-chip co-planar waveguide-based spin rectifier array with a large zero-bias sensitivity (around 34,500 mV/mW) and high efficiency (7.81%). Self-parametric excitation driven by voltage-controlled magnetic anisotropy is a key mechanism that contributes to the performance of the spin-rectifier array. We show that these spin rectifiers can wirelessly power a sensor at a radiofrequency power of -27 dBm.

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Raghav Sharma, Tung Ngo, Eleonora Raimondo, Anna Giordano, Junta Igarashi, Butsurin Jinnai, Shishun Zhao, Jiayu Lei, Yong-Xin Guo, Giovanni Finocchio, Shunsuke Fukami, Hideo Ohno, Hyunsoo Yang. 2024-08-02. Nanoscale spin rectifiers for harvesting ambient radiofrequency energy. https://doi.org/10.1038/s41928-024-01212-1

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