Reconfigurable training and reservoir computing in an artificial spin-vortex ice via spin-wave fingerprinting
Reconfigurable training and reservoir computing in an artificial spin-vortex ice via spin-wave fingerprinting
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DOI：
10.1038/s41565-022-01091-7
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发表时间：
2022-05-05
影响因子：
38.3
通讯作者：
Branford, Will R.
中科院分区：
文献类型：
--
作者：
Gartside, Jack C.;Stenning, Kilian D.;Branford, Will R.
强相互作用的人工自旋系统正在超越模仿自然发生的材料，成为从可重构磁振子到神经形态计算的多功能平台。通常，人工自旋系统包括具有单一磁化纹理的纳米磁体：共线宏观自旋或手性涡旋。通过调整纳米阵列的尺寸，我们已经实现了宏观自旋涡旋双稳态，并展示了一个四态的超材料自旋系统，“人工自旋涡旋冰”（ASVI）。ASVI可以托管具有强冰状顶点相互作用和低杂散偶极场的弱耦合涡旋的类伊辛宏观自旋。涡旋和宏自旋表现出截然不同的自旋波谱模拟模式的振幅控制和模式的频率偏移Δ f = 3.8 GHz。增强的bitextural微观状态空间产生了紧急的物理记忆现象，棘轮式涡注入和历史依赖的非线性衰减记忆时，通过全球磁场周期驱动。我们采用自旋波微观指纹快速，可扩展的读出涡旋和宏自旋人口，并利用这一自旋波水库计算。ASVI对不同的输入信号和目标信号进行非线性映射变换，并进行混沌时间序列预测。这使得高度可重构的磁振子行为，这是利用硬件神经形态计算。
Strongly interacting artificial spin systems are moving beyond mimicking naturally occurring materials to emerge as versatile functional platforms, from reconfigurable magnonics to neuromorphic computing. Typically, artificial spin systems comprise nanomagnets with a single magnetization texture: collinear macrospins or chiral vortices. By tuning nanoarray dimensions we have achieved macrospin-vortex bistability and demonstrated a four-state metamaterial spin system, the 'artificial spin-vortex ice' (ASVI). ASVI can host Ising-like macrospins with strong ice-like vertex interactions and weakly coupled vortices with low stray dipolar field. Vortices and macrospins exhibit starkly differing spin-wave spectra with analogue mode amplitude control and mode frequency shifts of Delta f = 3.8 GHz. The enhanced bitextural microstate space gives rise to emergent physical memory phenomena, with ratchet-like vortex injection and history-dependent non-linear fading memory when driven through global magnetic field cycles. We employed spin-wave microstate fingerprinting for rapid, scalable readout of vortex and macrospin populations, and leveraged this for spin-wave reservoir computation. ASVI performs non-linear mapping transformations of diverse input and target signals in addition to chaotic time-series forecasting.A nanomagnetic artificial spin ice array with two types of nanomagnets can host both magnetic macrospins and vortices. This enables highly reconfigurable magnon behaviour, which is leveraged for hardware neuromorphic computation.