Shangrun Lu

Order‐to‐disorder transitions in skyrmion lattices have been explored under spatially uniform stimuli, such as thermal or magnetic fields, which are significant for controlling collective skyrmion behavior for spintronic applications. However, under directional driving by an electric current, how the order of a skyrmion lattice evolves beyond melting into a liquid remains unclear. Here we show that a current‐driven skyrmion lattice does not enter a disordered phase, but instead undergoes a solid‐to‐conformal phase transition with periodically modulated local orientation, using in situ Lorentz transmission electron microscopy (L‐TEM). Unsupervised graph learning, combined with complementary structural order parameters, enables direct real‐time tracking of the lattice reordering. Correlation between orientational order and defect evolution reveals that the transition is mediated by transient dislocation proliferation during the development of the ordered state. These results establish a current‐induced order‐to‐order skyrmion transition and uncover conformal ordering as a distinct nonequilibrium structural state in topological particle assemblies.

Skyrmions carry robust topology, yet their geometry is highly tunable and can shape interactions, dynamics and functionality. However, how geometric confinement couples to helicity and reshapes the effective energy landscape in intrinsically anisotropic skyrmions remains unexplored. Here we demonstrate that skyrmion ellipticity and its magnetic‐field evolution are strongly helicity dependent in 500‐nm‐wide FeNiPdP nanostripes with anisotropic Dzyaloshinskii–Moriya interaction. Confinement compresses clockwise (CW)‐helicity skyrmions toward near‐circular profiles, whereas counterclockwise (CCW)‐helicity skyrmions elongate along the nanostripe axis, breaking the reciprocal ellipticity relation expected in unconfined geometries. Increasing the perpendicular field further reveals a monotonic circularization of CW skyrmions but a clear nonmonotonic response for CCW skyrmions. Energy analysis shows that confinement reshapes the field‐dependent energy landscape and shifts the optimal skyrmion geometry, giving rise to this nonlinear response. The nanostripe constraint also introduces a surface‐localized interstitial vortex texture in anisotropic skyrmions that can evolve into a vortex pair, consistent with our micromagnetic simulations. Our results establish helicity‐resolved confinement as a route to engineer anisotropic skyrmion morphology and emergent surface textures, enabling helicity‐programmable shape and interaction control for multistate skyrmion‐based devices.

Three‐dimensional (3D) topological spin textures host rich internal structures in thickness dimensions and enable emergent topological phenomena. However, whether their layer‐resolved textures and internal singularities fundamentally modify intralayer interactions lies beyond rigid‐tube interaction models and remains unexplored. Here we show that, in 3D hybrid skyrmion‐antiskyrmion strings, the layer‐dependent topology gives rise to interactions with a sign change across the film thickness, producing a switch between attraction and repulsion both among different layers within each texture and between neighboring 3D strings. This vertically asymmetric attractive‐repulsive interaction drives a tunable transition between square and triangular string lattices, in agreement with our experiment. Computational simulations identify quadrupolar Bloch points as internal topological junctions whose vertical migration mediates the intralayer competition between repulsive skyrmion segments near the surfaces and attractive antiskyrmion segments in the interior. We further show that the averaged topological charge quantifies the relative thickness fractions of the two competing topological segments and robustly captures the lattice phase boundary over a broad range of magnetic parameters. These findings highlight the importance of the surface‐bulk difference in topological materials and establish vertically asymmetric interactions as an intrinsic mechanism for topological phase control in 3D magnetic systems.