Fig. 1: Methods of controlling SOTs in spin source/FM structures.
From: Recent progress on controlling spin-orbit torques by materials design
a Strain engineering. Application of strain from the piezo substrate onto the film enhances the spin current. b Interface engineering. Inserting an oxide layer into the spin source/FM structure increases the transparency of the spin current. c Symmetry engineering. Spin current with z-polarization is prohibited by the mirror symmetry (left), and allowed when no mirror plane appears (right).
