This paper provides a tutorial overview over recent vigorous efforts to develop computing systems based on spin waves instead of charges and voltages. Spin-wave computing can be considered as a subfield of spintronics, which uses magnetic excitations for computation and memory applications. The tutorial combines backgrounds in spin-wave and device physics as well as circuit engineering to create synergies between the physics and electrical engineering communities to advance the field towards practical spin-wave circuits. After an introduction to magnetic interactions and spin-wave physics, all relevant basic aspects of spin-wave computing and individual spin-wave devices are reviewed. The focus is on spin-wave majority gates as they are the most prominently pursued device concept. Subsequently, we discuss the current status and the challenges to combine spin-wave gates and obtain circuits and ultimately computing systems, considering essential aspects such as gate interconnection, logic level restoration, input-output consistency, and fan-out achievement. We argue that spin-wave circuits need to be embedded in conventional CMOS circuits to obtain complete functional hybrid computing systems. The state of the art of benchmarking such hybrid spin-wave--CMOS systems is reviewed and the current challenges to realize such systems are discussed. The benchmark indicates that hybrid spin-wave--CMOS systems promise ultralow-power operation and may ultimately outperform conventional CMOS circuits in terms of the power-delay-area product. Current challenges to achieve this goal include low-power signal restoration in spin-wave circuits as well as efficient spin-wave transducers.

中文翻译：

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自旋波计算简介

本文概述了最近为开发基于自旋波而不是电荷和电压的计算系统所做的积极努力。自旋波计算可以被认为是自旋电子学的一个子领域，它使用磁激励进行计算和存储应用。本教程结合了自旋波和器件物理学以及电路工程的背景，以在物理学和电气工程社区之间建立协同作用，以推动该领域朝着实用的自旋波电路发展。在介绍了磁相互作用和自旋波物理学之后，回顾了自旋波计算和单个自旋波器件的所有相关基本方面。重点是自旋波多数门，因为它们是最突出的器件概念。随后，我们讨论了结合自旋波门并获得电路和最终计算系统的现状和挑战，考虑了门互连、逻辑电平恢复、输入输出一致性和扇出实现等基本方面。我们认为自旋波电路需要嵌入到传统的 CMOS 电路中才能获得完整的功能混合计算系统。回顾了对这种混合自旋波-CMOS 系统进行基准测试的最新技术，并讨论了实现这种系统的当前挑战。基准测试表明，混合自旋波-CMOS 系统有望实现超低功耗操作，并可能最终在功率延迟面积乘积方面优于传统 CMOS 电路。