Spintronics exhibits significant potential for a neuromorphic computing system with high speed, high integration density, and low dissipation. In this article, we propose an ultralow-dissipation skyrmion-based nanodevice composed of a synthetic antiferromagnet (SAF) and a piezoelectric substrate for neuromorphic computing. Skyrmions/skyrmion bubbles can be generated in the upper layer of an SAF with a weak anisotropy energy (E_a). Applying a weak electric field on the heterostructure, interlayer antiferromagnetic coupling can be manipulated, giving rise to a continuous transition between a large skyrmion bubble and a small skyrmion. This thus induces a variation of the resistance of a magnetic tunneling junction that can mimic the potentiation/depression of a synapse and the leaky-integral-and-fire function of a neuron at a cost of a very low energy consumption of 0.3 fJ. These results pave a way to ultralow power neuromorphic computing applications.

A skyrmionium is composed of two skyrmions with opposite skyrmion numbers and different sizes in the same track. In recent years, the motion of a skyrmionium driven by spin-polarized current has been investigated. However, the motion of a skyrmionium driven by a spin wave has not been reported. In this paper, we report our work concerning the numerical analysis of spin wave-driven motion of a skyrmionium in a nanotrack. The results show that the motion of a skyrmionium was significantly influenced by varying the frequency and amplitude of the AC magnetic field for exciting a spin wave, the distance between the spin wave source and the skyrmionium, the damping coefficient of the ferromagnetic track, and the track width. We found skyrmionium deformation during its initial motion process, but its shape could be recovered as it moved farther away from the spin wave source. Additionally, a series of velocity peaks were observed in the frequency range between 25 GHz and 175 GHz. When compared to a skyrmion, the skyrmionium could be driven by a spin wave to move in a wider frequency range at a higher velocity, and the velocity of the skyrmionium kept increasing with the increase in the track width till the track edge was far away from the skyrmionium. The result offers skyrmionium potential applications in wide-frequency spintronic devices.

Magnetoelectric (ME) composite materials have a stronger ME coupling effect in resonant states than in non-resonant states. Typically, these resonant states appear at frequencies of several tens of kHz or even MHz. However, for DC and low-frequency applications of ME composites, obtaining a high ME response is critical. In recent years, many studies have attempted to improve the DC and low-frequency ME performance of ME composite materials at frequencies below 1 kHz. This article reviews the research and major progress in this field and investigates the application of other methods.

Filamentization of 2G-HTS tapes provides a means for significant reduction of magnetization AC losses in coated conductors. Photolithography followed by dry etching is one of the approaches to `top-down' filamentization of REBCO (RE=rare earth) and shunt layers. Some of the issues associated with this approach include REBCO undercuts, as well as the complexity and cost of the process. In this work, we present results on a study aimed at developing an alternative, `bottom-up' filamentization technique that is free of undercuts, has low cost, high throughput and is readily scalable. Here, the buffer tape is striated by mechanically removing thin stripes of the buffer stack, followed by the REBCO Metal Organic Chemical Vapor Deposition (MOCVD) process. We couple this technique with a low cost deposition of the silver shunt layer using electrodeposition instead of sputtering and study the conditions for selective electrodeposition on the superconducting filaments.

In the ‘Beyond Moore’s Law’ era, information devices are expected to exhibit advantages, including small sizes, high processing speeds, and low power and dissipation. Novel magnetic information devices with these advantages are made of heavy metal (HM)/ferromagnet (FM) composites. Owing to an asymmetric structure, the anisotropic exchange coupling, named the interfacial Dzyaloshinskii–Moriya interaction (iDMI), is generated at the HM/FM interface. This iDMI plays a fundamental role in stabilizing non-trivial topological magnetic solitons, such as magnetic skyrmions and chiral domain walls (DWs). On the other hand, the iDMI also influences the magnetic dynamics, including ferromagnetic resonance (FMR), spin wave, and the motion of the chiral DWs and skyrmions. These magnetic dynamic behaviors are the base of the functions of novel magnetic information devices. Therefore, the influence of the iDMI on magnetic dynamics has attracted wide attention in recent years. In this topical review, we give a detailed introduction to and discussion about recent investigations of the iDMI-relevant magnetic dynamics of HM/FM bilayer systems. Especially, this review concentrates on the individual contributions of the inner iDMI and the boundary iDMI to magnetic dynamics. This review consists of the following sections: (a) an introduction about the background, the basic theory of magnetic dynamics, and the iDMI; (b) a review of the effects of the iDMI on the propagation of spin wave. Owing to the iDMI, the dispersion relationship of the spin wave is asymmetric, which results in various interesting phenomena. This not only offers a precise method for measuring the iDMI constant, but also gives rise to potential applications for novel magnonic devices. (c) A review of the effects of the iDMI on FMR. In general, the iDMI is thought to have little impact on the FMR for uniform precession. However, a unique iDMI-relevant mode was still observed in the FMR spectra owing to the non-parallel alignment of magnetic moments as a result of the boundary iDMI. (d) A review about the motion of DWs with a chiral structure due to the iDMI. The iDMI plays a fundamental role in the high velocity of the chiral DWs. Meanwhile, the iDMI also results in the tilting of the DW plane, and the mechanism for this tilting has been widely investigated. The tilting of the DW plane may be depressed by the interlayer exchange coupling. (e) Finally, we summarize the review and give an outlook.