Current-induced effective magnetic field in La0.67Sr0.33MnO3/LaAlO3/SrTiO3 structures

We investigate the current-induced effective magnetic field Heff in La0.67Sr0.33MnO3 (18)/LaAlO3(0,2,6)/SrTiO3 (LSMO/LAO/STO) structures by using the planar Hall effect (PHE), where numbers in parentheses give the nominal thickness of the given layer in unit cells. In all the structures, applying an in-plane current creates an in-plane Heff orthogonal to the current direction, and the direction of Heff for the LSMO/LAO(6)/STO structure is opposite to that for the LSMO/LAO(0,2)/STO structures. At low temperature, the sign of the PHE coefficient originating from the spin-orbit interaction (SOI) for the LSMO/LAO(6)/STO structure is also opposite to that for the LSMO/LAO(0,2)/STO structures, which suggests that the SOI in the LSMO layer is modified by the LAO(6)/STO structure. The direction of Heff is consistent with that induced by the SOI at the interface of the LSMO layer, and thus the opposite-polarity Heff detected in the LSMO/LAO(6)/STO structure can be related to the SOI variation induced by the LAO(6)/STO structure.