Magnetic skyrmions are nanoscale topologically nontrivial spin textures characterized by integer topological charges, particle-like transport behavior, high stability, low critical driving current density, and rich internal degrees of freedom. Owing to these properties, they have been regarded as promising information carriers for next-generation low-power and high-density spintronic devices. In this review, we summarize recent progress in the writing, manipulation, material development, and device design of magnetic skyrmions, with particular emphasis on the underlying physical mechanisms and their relevance to functional spintronic applications. We first discuss the controllable writing and deletion of skyrmions. Various approaches, including spin-polarized current injection, spin-orbit torque, thermal activation, electron/ion-beam irradiation, local magnetic fields, geometric confinement, intrinsic material defects, and strain engineering, are reviewed. These studies show that skyrmion nucleation and annihilation are generally governed by the competition among exchange interaction, magnetic anisotropy, dipolar interaction, Dzyaloshinskii–Moriya interaction, Joule heating, and boundary- or defect-induced energy barriers. Recent experiments further demonstrate deterministic and highly reproducible electrical writing and deletion of individual skyrmions, skyrmion bubbles, antiskyrmions, and skyrmion packets, indicating that skyrmion manipulation has gradually evolved from statistical domain conversion to addressable control of single topological objects.

We then review the determination and manipulation of skyrmion helicity, which describes the in-plane spin rotation within the domain wall and distinguishes Bloch-type, Néel-type, and hybrid skyrmions. Lorentz transmission electron microscopy, tilted-field imaging, micromagnetic simulations, and current- or thermally assisted spin-orbit-torque manipulation provide effective routes to identify and control helicity. In centrosymmetric and dipolar-interaction-dominated systems, helicity may exhibit bistability, multistability, continuous tunability, and even three-dimensional variation along the sample thickness. These results indicate that helicity is not merely a structural descriptor, but an internal degree of freedom that can be used for multilevel information encoding and dynamical control. Closely related to helicity is the skyrmion Hall effect, which originates from the transverse gyroforce associated with a nonzero topological charge. We summarize several strategies for controlling the skyrmion Hall angle, including synthetic antiferromagnetic compensation, helicity engineering, boundary-guided motion, voltage-controlled magnetic anisotropy, and specially designed magnetic boundaries. These approaches show that the skyrmion Hall effect can be suppressed, compensated, or even utilized, depending on the intended device function.

Material platforms are another central issue for skyrmion physics and applications. We review representative skyrmion-hosting systems, including B20 chiral magnets, metallic multilayers, centrosymmetric frustrated or dipolar magnets, synthetic antiferromagnets, and two-dimensional van der Waals magnets and heterostructures. In particular, van der Waals magnets provide atomically sharp interfaces, flexible stacking, tunable interfacial coupling, and new opportunities for stabilizing skyrmions at or above room temperature. Recent advances in Fe₃GeTe₂-based heterostructures, Fe_5–δGeTe₂, Fe₃GaTe₂, and Cr_1.9Te₂ demonstrate that interfacial Dzyaloshinskii–Moriya interaction, vacancy ordering, thickness control, field cooling, and temperature-dependent magnetic anisotropy can be used to stabilize Néel-type skyrmions, zero-field skyrmion lattices, and reversible topological phase transitions between skyrmions and meron–antimeron chains. Finally, we discuss skyrmion-based device concepts, including spin-torque nano-oscillators, racetrack memories, RF mixers, microwave detectors, and spin-pumping-based readout schemes. These devices exploit skyrmion gyration, breathing modes, topological charge, helicity, interlayer coupling, and skyrmion packets to realize microwave signal generation, multibit transport, low-power actuation, and potentially neuromorphic functionalities.

Overall, magnetic skyrmion research has developed from the discovery of topological spin textures to the engineering of controllable information carriers. The key physical results reviewed here demonstrate that skyrmion writing, helicity control, Hall-angle manipulation, material optimization, and device integration are deeply interconnected. Future progress will require high-temperature and zero-field material platforms, reliable single-skyrmion writing and readout, defect-tolerant transport, improved signal-to-noise ratio, and compatibility with scalable nanofabrication and CMOS technologies. Continued integration of condensed-matter physics, materials design, advanced magnetic imaging, micromagnetic simulation, and device engineering will be essential for transforming magnetic skyrmions from observable topological quasiparticles into manufacturable and integrable functional units for spintronic technologies.