Fig. 2: Current-driven SOT switching.
a, b show the SOT switching for the collinear case between the spin polarization (σ) and the easy axis (σ∥EA). b The current-driven SOT switching shows the deterministic switching without external magnetic field, i.e., field-free switching, where the magnetic field Hz has not effect on the switching polarity. c, d show the SOT switching for the orthogonal case of σ⊥EA, where a Hz is needed for deterministic switching. d For the σ⊥EA case, an external magnetic field Hz is needed to break the mirror symmetry between +mx and −mx for deterministic SOT switching, as indicated by the opposite SOT switching polarities under Hz = ±100 Oe. e, SOT switching for the MTJ scaling down from 4 µm × 8 µm to 100 nm × 200 nm (σ∥EA).
