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We show a topological spin texture called "bimeronium" in magnets with in-plane magnetization. It is a topological counterpart of skyrmionium in perpendicularly magnetized magnets and can be seen as a combination of two bimerons with opposite topological charges. We report the static structure and spin-orbit-torque-induced dynamics of an isolated bimeronium in a magnetic monolayer with frustrated exchange interactions. We study the anisotropy and magnetic field dependences of a static bimeronium. We also explore the bimeronium dynamics driven by the damping-like spin-orbit torque. We find that the bimeronium shows steady rotation when the spin polarization direction is parallel to the easy axis. Moreover, we demonstrate the annihilation of the bimeronium when the spin polarization direction is perpendicular to the easy axis. Our results are useful for understanding the fundamental properties of bimeronium structures and may offer an approach to build bimeronium-based spintronic devices. [ABSTRACT FROM AUTHOR]

Energy harvesting is getting significant interest due to the emergence of Internet of Things (IoT). As IoT devices are required to generate power on their own, several researchers are studying ferroelectric materials for voltage generation. However, ferroelectric materials suffer from high resistance at low frequencies, which reduces the output power. Domain wall propagation in ferromagnetic materials, as induced by stress and a pickup voltage using coils, is investigated as an alternate form of energy harvesting. Such studies, which are reported in multiferroic structures, feature a voltage applied to induce the stress, which defeats the purpose of self‐power generation. Here, power generation from mechanical vibrations in purely ferromagnetic structures is shown. These results are achieved by showing that the domain walls can be moved entirely by stress in a trilayer stack of ferromagnetic microwires. The use of flexible substrates with low Young's modulus and a trilayer magnetic stack enables the achievement of significant magnetization rotation or domain wall motion even from ambient vibrations. Here, the rotation of magnetization or domain wall motion is exploited to induce voltages in the pickup coils. The results shown here provide an alternative way to power IoT devices. Energy harvesting is experimentally demonstrated based on domain wall motion in magnetic microwires. FeCo‐based microwires with an anisotropy in the transverse direction change their magnetization to the longitudinal direction with the application of stress. Such a change in magnetization in the presence of a time‐varying stress could be harvested as voltage for pico‐Internet of Things devices. [ABSTRACT FROM AUTHOR]

A magnetic skyrmionium is a skyrmion-like structure, but carries a zero net skyrmion number which can be used as a building block for non-volatile information processing devices. Here, we study the dynamics of a magnetic skyrmionium driven by propagating spin waves. It is found that the skyrmionium can be effectively driven into motion by spin waves showing a tiny skyrmion Hall effect, whose mobility is much better than that of the skyrmion at the same condition. We also show that the skyrmionium mobility depends on the nanotrack width and the damping coefficient and can be controlled by an external out-of-plane magnetic field. In addition, we demonstrate that the skyrmionium motion driven by spin waves is inertial. Our results indicate that the skyrmionium is a promising building block for building spin-wave spintronic devices. [ABSTRACT FROM AUTHOR]