Controlling skyrmion lattice orientation with local magnetic field gradients

Abstract

Precise control over the formation and arrangement of magnetic skyrmion lattices is essential for understanding their emergent behavior and advancing their integration into spintronic and magnonic devices. Using single-pass magnetic force microscopy (MFM), we establish a protocol to nucleate and manipulate skyrmion lattices in soft magnetic CoFeB. By tuning the scan-line spacing to match the intrinsic stripe domain periodicity, the stray field gradient from the MFM tip induces reversible transitions from stripe domains to isolated skyrmions and locally ordered lattices. The resulting skyrmion positions are extracted to compute the local orientational order parameter ψ6, enabling quantitative evaluation of lattice ordering. A systematic improvement in ⟨|ψ6|⟩ is observed with repeated scanning, indicating a transition from a disordered state to ordered hexagonal arrangements. Furthermore, we demonstrate that the lattice orientation can be directly rotated by changing the scanning direction, as confirmed through real-space analysis and fast Fourier transformations. This method enables the local creation, reordering, and deletion of metastable skyrmions on demand, providing unprecedented control over lattice symmetry, order, and orientation.