Spectral fingerprinting: microstate readout via remanence ferromagnetic resonance in artificial spin ice
Spectral fingerprinting: microstate readout via remanence ferromagnetic resonance in artificial spin ice
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DOI：
10.1088/1367-2630/ac608b
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发表时间：
2021-06
影响因子：
3.3
通讯作者：
A. Vanstone;J. Gartside;K. Stenning;T. Dion;D. Arroo;W. Branford
中科院分区：
文献类型：
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作者：
A. Vanstone;J. Gartside;K. Stenning;T. Dion;D. Arroo;W. Branford
人工自旋冰(ASIS)是一种磁性超材料，由几何平铺的强相互作用纳米磁体组成。这些系统从多体系统的基本物理到在神经形态计算、逻辑和最近可重构的磁子学中的潜在应用，都引起了人们的极大兴趣。到目前为止，磁振子学对ASI的研究主要集中在场中GHz自旋波的响应、外场的卷积效应、纳米制造缺陷(猝灭无序)和微态相关的偶极场景观。在这里，我们研究了自旋波响应的零场测量，并展示了它提供系统微态的‘光谱指纹’的能力。去掉外加磁场，可以从自旋波谱中解卷出对反转动力学的不同贡献，直接测量偶极磁场强度和猝灭无序以及净磁化。我们通过测量具有相同(零)磁化程度的三个微态的ASI来证明这种方法的有效性和灵敏度，通过磁测量无法区分这些微态。零场自旋波响应提供了每个状态的不同光谱指纹，从而实现了快速、可扩展的微状态读出。随着人工自旋系统朝着设备实现的方向发展，零场功能对于最大限度地减少与电磁铁相关的功耗至关重要。几个提出的硬件神经形态计算方案依赖于利用ASI微态的动态测量来执行计算，而光谱指纹为其提供了潜在的解决方案。
Artificial spin ices (ASIs) are magnetic metamaterials comprising geometrically tiled strongly-interacting nanomagnets. There is significant interest in these systems spanning the fundamental physics of many-body systems to potential applications in neuromorphic computation, logic, and recently reconfigurable magnonics. Magnonics focused studies on ASI have to date have focused on the in-field GHz spin-wave response, convoluting effects from applied field, nanofabrication imperfections (‘quenched disorder’) and microstate-dependent dipolar field landscapes. Here, we investigate zero-field measurements of the spin-wave response and demonstrate its ability to provide a ‘spectral fingerprint’ of the system microstate. Removing applied field allows deconvolution of distinct contributions to reversal dynamics from the spin-wave spectra, directly measuring dipolar field strength and quenched disorder as well as net magnetisation. We demonstrate the efficacy and sensitivity of this approach by measuring ASI in three microstates with identical (zero) magnetisation, indistinguishable via magnetometry. The zero-field spin-wave response provides distinct spectral fingerprints of each state, allowing rapid, scaleable microstate readout. As artificial spin systems progress toward device implementation, zero-field functionality is crucial to minimize the power consumption associated with electromagnets. Several proposed hardware neuromorphic computation schemes hinge on leveraging dynamic measurement of ASI microstates to perform computation for which spectral fingerprinting provides a potential solution.