Tuning Rashba-Dresselhaus effect with ferroelectric polarization at asymmetric heterostructural interface.

The spin-orbit interaction (SOI) plays an essential role in materials properties, and controlling its intensity has great potential in the design of materials. In this work, asymmetric [(La 0.7 Sr 0.3 MnO 3 ) 8 /(BaTiO 3 ) t /(SrTiO 3 ) 2 ] 8 superlattices were fabricated on (001) SrTiO 3 substrate with SrO or TiO 2 termination, labelled as SrO-SL and TiO 2 -SL, respectively. The in-plane angular magnetoresistance of the superlattices shows a combination of two- and four-fold symmetry components. The coefficient of two-fold symmetry component has opposite sign with current I along [100] and [110] directions for TiO 2 -SL, while it has the same sign for SrO-SL. Detailed study shows that the asymmetric cation inter-mixing and ferroelectricity-modulated electronic charge transfer induce asymmetric electronic potential for SrO-SL with dominating Rashba SOI, and symmetric electronic potential for TiO 2 -SL with dominating Dresselhaus SOI induced by BaTiO 3 . This work shows that the Rashba and Dresselhaus SOIs are sensitive to the ferroelectric polarization in the asymmetric structure.