NANO42 – Spin Wave Based Computing: The Road from Gates to Circuits

  In this presentation we provide an overview of recent efforts to develop computing systems based on spin waves instead of charges and voltages. Note that Spin-wave computing can be considered a subfield of spintronics, which uses magnetic excitations for computation and memory applications. We start with an introduction to magnetic interactions, spin-wave physics, and basic spin-wave computing mechanisms. Subsequently, we review individual spin-wave devices while focusing on spin-wave majority gates as they are the most prominently pursued spin-wave device concept. Afterwards, we discuss the state-of-the-art and the challenges to combine spin-wave gates to obtain circuits and ultimately computing systems, by considering essential aspects, e.g., gate interconnection, logic level restoration, input-output consistency, and fan-out achievement. Then, we argue that spin-wave circuits need to be embedded into conventional complementary metal-oxide-semiconductor (CMOS) circuits to obtain complete functional hybrid computing systems and discus the potential performance of such hybrid spin-wave-CMOS systems and challenges towards their practical realization. Our estimates indicate that hybrid spin-wave-CMOS systems exhibit ultralow-power operation and may ultimately outperform conventional CMOS circuits in terms of power-delay-area product. Finally, we briefly present the SPIDER project (EC contract number 101070417) approach, which is the first ever attempt to experimentally demonstrate the feasibility of hybrid spin-wave-CMOS systems.