Artificial Spin Ice for Rewritable Magnonics

用于可重写磁振子学的人造旋转冰

• 批准号: EP/X015661/1
• 负责人: William Branford
• 金额: $ 109.57万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX015661%2F1
• 关键词: Artificial; Spin; Ice; Rewritable; Magnonics

The key physical concept of this project is that magnetic spin-waves, or their quanta magnons, can act as information carriers and be manipulated for information processing & computation. Conventional computers rely on physically moving particles (electrons), and vast amounts of energy are wasted by ohmic loss and heating induced by electronic transit, both within the logic devices and particularly between the separate logic and storage media. If current trends continue, computation will consume one third of global energy production by 2040, and consequently increasing computational energy efficiency is a critical challenge. Because magnets can transfer information from one device to the next without the exchange of any physical particles and have intrinsic passive data storage, 'magnonics' is in principle orders of magnitude more energy efficient than standard electronics & a promising route to aiding the global energy crisis.Magnets are used in memory devices as they passively retain information written into them (non-volatile). This project will enable creation of coupled arrays of nanomagnets that can be viewed as both memory and processor where novel circuits can be written and reprogrammed at will. Our ability to accomplish this exploits a technique which we have developed called All-Optical Magnetic Switching (AOMS), allowing controlled writing of any individual nanomagnet in the array with a low-power laser like a Blu-Ray player, plus world-leading expertise harnessing nanomagnetic arrays for spin-wave information processing - including world-first demonstration of magnonic neuromorphic computation in an array of interacting nanomagnets.Each ferromagnetic nanoisland stores a fixed average magnetization, but the magnetic moment is not completely static, instead precessing around the average direction at characteristic resonant frequencies in the microwave (GHz) range. For a single nanomagnet, the frequency is controlled by its size and shape in the same way that shortening a guitar string changes the note. Coupled arrays of nanomagnets have distinct spectral fingerprints and these can be used for readout of states. The magnonic resonances are also highly sensitive to the magnetic texture of each island, and one of our recent breakthroughs exploits this to prepare bistable vortex & macrospin islands exhibiting far greater functional magnonic flexibility versus conventional all-macrospin systems.It is already well established from simulations that the exact microstate of the array controls the resonant frequency of the magnons and that we can realise switches and transistor type devices for logic functions where the magnetic state controls whether magnons of a specific frequency can pass through or not. This project aims to integrate different functional elements and explore prototype magnonic components and circuits. It is highly adventurous, and there are many experimental challenges to overcome to realise fully magnonic computation. For example, a process called damping causes travelling spin waves to attenuate rapidly with both time and distance. This presents a challenge in terms of completing the full computation before information is lost, as well as representing a source of energy inefficiency - though it can be avoided using resonant 'standing wave' magnons with which our scheme also functions. Although it is straightforward to measure these 'standing wave' magnons in a large array, detecting travelling magnons in nanoscale device structures is at the edge of state-of-the-art capabilities. In this project we aim to develop and expand these capabilities, building on our expertise and establish fundamental understanding of the physics of coupling, synchronization, transmission, and loss between different magnonic crystal states, and deliver a fruitful playground to explore novel computation architectures.

该项目的关键物理概念是磁性自旋波或其量子磁振子可以作为信息载体并被操纵进行信息处理和计算。传统的计算机依赖于物理上移动的粒子（电子），大量的能量被浪费在逻辑设备内，特别是在单独的逻辑和存储介质之间，由电子传输引起的欧姆损耗和发热。如果目前的趋势继续下去，到2040年，计算将消耗全球能源生产的三分之一，因此提高计算能源效率是一项重大挑战。由于磁体可以在不交换任何物理粒子的情况下将信息从一个设备传输到另一个设备，并且具有固有的被动数据存储，“磁体学”原则上比标准电子设备节能几个数量级，并且是帮助全球能源危机的有希望的途径。磁铁用于存储设备，因为它们被动地保留写入其中的信息（非易失性）。这个项目将创造纳米磁体的耦合阵列，它可以被看作是存储器和处理器，其中新的电路可以随意写入和重新编程。我们实现这一目标的能力利用了我们开发的一种叫做全光磁开关（AOMS）的技术，允许用像蓝光播放器一样的低功率激光在阵列中控制任何单个纳米磁体的写入，加上世界领先的利用纳米磁体阵列进行自旋波信息处理的专业知识——包括世界上第一次在相互作用的纳米磁体阵列中进行磁神经形态计算的演示。每个铁磁纳米岛存储一个固定的平均磁化强度，但磁矩不是完全静止的，而是在微波（GHz）范围内的特征谐振频率下围绕平均方向进动。对于单个纳米磁铁，其频率由其大小和形状控制，就像缩短吉他弦改变音符一样。纳米磁体的耦合阵列具有明显的光谱指纹，可以用于状态的读出。磁共振对每个岛的磁性结构也高度敏感，我们最近的突破之一就是利用这一点来制备双稳态涡旋和巨自旋岛，与传统的全巨自旋系统相比，它们表现出更大的功能性磁灵活性。从模拟中已经很好地确定了阵列的精确微状态控制着磁振子的谐振频率，并且我们可以实现用于逻辑功能的开关和晶体管型器件，其中磁态控制特定频率的磁振子是否可以通过。本项目旨在整合不同的功能元件，探索原型磁元件和电路。这是非常冒险的，并且有许多实验挑战要克服，以实现完全的磁振子计算。例如，一种称为阻尼的过程使行进的自旋波随时间和距离迅速衰减。这对在信息丢失之前完成完整计算提出了挑战，同时也代表了能源效率低下的来源-尽管可以使用谐振“驻波”磁振子来避免它，我们的方案也可以使用它。虽然在一个大阵列中测量这些“驻波”磁振子很简单，但在纳米级器件结构中检测行磁振子是最先进的能力。在这个项目中，我们的目标是发展和扩展这些能力，建立我们的专业知识，并建立对不同磁振子晶体状态之间的耦合，同步，传输和损失的物理的基本理解，并提供一个富有成效的平台来探索新的计算架构。

项目成果

Perspective on unconventional computing using magnetic skyrmions

• DOI: 10.1063/5.0148469
• 发表时间: 2023-03
• 期刊: ArXiv
• 作者: O. Lee;Robin Msiska;M. Brems;M. Kläui;H. Kurebayashi;K. Everschor-Sitte

Reconfigurable spinwave dispersion in continuous magnetic layer induced via artificial spin ice based magnonic crystal

人工自旋冰基磁力晶体诱导连续磁层中的可重构自旋波色散

• DOI: 10.1109/intermagshortpapers58606.2023.10228521
• 发表时间: 2023
• 作者: Dion T

Task-adaptive physical reservoir computing.

• DOI: 10.1038/s41563-023-01698-8
• 发表时间: 2024-01
• 期刊: NATURE MATERIALS
• 影响因子: 41.2
• 作者: Lee, Oscar;Wei, Tianyi;Stenning, Kilian D;Gartside, Jack C;Prestwood, Dan;Seki, Shinichiro;Aqeel, Aisha;Karube, Kosuke;Kanazawa, Naoya;Taguchi, Yasujiro;Back, Christian;Tokura, Yoshinori;Branford, Will R;Kurebayashi, Hidekazu
• 通讯作者: Kurebayashi, Hidekazu