Fig. 3

Topological unwinding of the metastable SkS-L under current. a Variation in Δρ _yx at the c₃–c₄ pair for various pulse magnitudes in response to repeated in-plane pulses. b Δρ _yx vs. in-plane pulse number at the c₅–c₆ pair for an in-plane current pulse of +8.2 × 10⁶ A m⁻². Δρ _yx, a good measure of the topological Hall signal, is obtained by offsetting the ρ _yx value before applying the writing pulse to zero. Labels, such as “8.2”, represent the in-plane pulse magnitude used in the measurements, expressed in the unit of 10⁶ A m⁻². + (closed symbols) denotes the current flowing from c₁ to c₂ (see Fig. 2c, d), and +/– (open symbols) denotes the pulse sequence in which positive and negative pulses are applied in an alternating manner. Measurements were performed at 15 K and 0.249 T with a fixed pulse width of 25 ms