Observation of stripes and biskyrmions under current excitations in a microdevice based on a bilayered manganites La_2−2xSr_1+2xMn₂O₇ with x = 0.315. (a) Schematic of the microdevice. (b), (c) Scanning-ion-microscopy images of the plane and cross-section views of the microdevice. (d)–(o) Lorentz TEM images of stripes and biskyrmions obtained under current excitations. Changes in magnetic configurations with increasing current J (in unit of 10⁷ A/m²), obtained under a magnetic field of 0.3 T applied normal to the (001)-plane device plate at 20 K. (d)–(g) A mixed state of screws and biskyrmions at J = 4.8 × 10⁷ A/m²–9.0 × 10⁷ A/m². (h)–(k) A mixed state at finely tuned J (7.5 × 10⁷ A/m²–7.8 × 10⁷ A/m²) and (l)–(o) a single-phase biskyrmion lattice state at J = 2.0 × 10⁷ A/m²–6.0 × 10⁷ A/m². Red arrows indicate the current direction. The insert at the right bottom corner shows the biskyrmion lattice without current excitation. Scale bars in panels (d), (h), and (l) correspond to 500 nm. Reprinted with permission from Ref. [19]. Copyright 2014, Nature Publishing Group.