The pursuit of more efficient computing architectures drives investigation into alternatives to traditional electronics, with soliton-based systems offering a promising path forward. Moritz A. Goerzen, Tim Drevelow, Soumyajyoti Haldar, and colleagues demonstrate that specific magnetic structures, known as bimerons and antibimerons, possess characteristics that make them particularly well-suited for advanced computing applications. Their research reveals these solitons exhibit greater versatility and potential for complex interactions than previously studied magnetic skyrmions, potentially overcoming limitations in data processing. By employing computational modelling, the team predicts the stable coexistence of bimerons and antibimerons within a van der Waals heterostructure composed of iron germanium telluride and chromium germanium telluride, and importantly, establishes that their behaviour differs fundamentally from skyrmions due to unique symmetry properties, opening new avenues for spintronic device development.
Topological Spin Textures for Energy Efficient Computing
Soliton-based computing offers a promising path towards energy-efficient information processing, and topological spin textures, such as bimerons and antibimerons, are viable candidates for realising such devices. These textures, characterised by a unique topological charge, demonstrate inherent stability against external disturbances, but their practical application requires understanding their dynamic behaviour and lifetime. This work investigates the lifetime of bimerons and antibimerons in two-dimensional magnets, focusing on how material properties and external stimuli influence them. Micromagnetic simulations model the temporal evolution of these textures under various conditions, providing insights into the mechanisms governing their decay.
The simulations reveal that the lifetime of bimerons and antibimerons strongly depends on the strength of the Dzyaloshinskii, Moriya interaction, magnetic anisotropy, and the presence of defects. A stronger Dzyaloshinskii, Moriya interaction generally leads to increased stability, while defects accelerate decay. The interplay between these factors determines the overall robustness of the textures against thermal fluctuations and external perturbations. Remarkably long lifetimes, exceeding several nanoseconds under optimised conditions, are achievable, which is crucial for potential applications in data storage and processing. Careful control of the Dzyaloshinskii, Moriya interaction strength and defect density can significantly improve their performance, paving the way for novel spintronic devices based on these topological spin textures.
Skyrmion Dynamics in Heterostructured Thin Films
Emerging magnetic architectures offer a promising avenue to overcome limitations of conventional information technologies. Magnetic skyrmions are widely considered for in-situ processing devices due to their inherent mobility and enhanced lifetime in materials exhibiting broken inversion symmetry. These nanoscale magnetic whirls represent potential information carriers, and their controlled manipulation is crucial for device functionality. This research focuses on understanding and optimising the dynamics of these skyrmions under various external stimuli, including magnetic fields and spin-orbit torques.
Investigations involve fabricating thin-film heterostructures using magnetron sputtering. The magnetic properties of these structures are characterised using techniques such as vibrating sample magnetometry, magneto-optical Kerr effect microscopy, and transmission electron microscopy. Skyrmion formation and annihilation are observed and tracked using real-time imaging, allowing for detailed analysis of their velocity, trajectory, and stability. Numerical simulations, based on micromagnetic theory, complement the experimental findings, providing insights into the underlying physical mechanisms governing skyrmion behaviour and aiding in the design of optimised device architectures.
Skyrmions and Bimerons in 2D Materials
Research focuses on skyrmions and bimerons, covering their fundamental properties, stability, dynamics, and potential applications, particularly in 2D materials and heterostructures. The Dzyaloshinskii-Moriya interaction is crucial for stabilising skyrmions, especially interfacial Dzyaloshinskii-Moriya interaction in heterostructures, controlling their properties. The underlying principle is topological magnetism, linked to their stability and potential for information storage and processing. Research explores applications including neuromorphic computing, information storage in low-power memory devices, and novel spintronic devices.
Finding ways to create, control, and stabilise skyrmions in 2D materials involves tuning the Dzyaloshinskii-Moriya interaction, controlling anisotropy, and engineering defects. There is growing interest in bimerons and other less-studied topological textures, aiming to understand their properties and how to create them. Controlling skyrmion motion is crucial, with research focusing on understanding and controlling the skyrmion Hall effect and developing efficient ways to move them. Research investigates the topological protection of skyrmions and bimerons against perturbations and defects. Techniques used include Density Functional Theory for materials design, Ginzburg-Landau Theory for modelling magnetic textures, and micromagnetic simulations. This bibliography represents a comprehensive overview of the current state of research in topological magnetism, with a strong focus on skyrmions and bimerons in 2D materials, highlighting their potential for a wide range of applications.
Bimerons Outperform Skyrmions in Spintronics Potential
This research demonstrates that bimerons and antibimerons exhibit greater potential for non-linear interactions than skyrmions and antiskyrmions, making them strong candidates for advanced spintronic applications. Through computational methods, the team predicted the coexistence of these solitons in a van der Waals heterostructure composed of iron germanium telluride and chromium germanium telluride. Bimerons possess unique properties stemming from their structural symmetry and the unbroken rotational symmetry within easy-plane magnets, distinguishing them from skyrmions. The findings highlight the enhanced stability of these solitons, driven by entropic effects and non-local thermal excitations, and demonstrate that this stabilization does not differentiate between particles and antiparticles below a certain magnetic field. This entropic stabilization exceeds that observed in other systems.