Computational exploration of Rashba-Dresellhaus effect in bulk perovskite oxides and heterostructure interfaces

Abstract

Harnessing the spin orbit coupling (SOC) driven manifestations in electronic structure for device application comprises one of the challenging fields in spintronics application. One such avenue is via the Rashba-Dresselhaus (RD) effect, which leads to the splitting of spin states at the band edges in momentum space enabling the creation of separate spin channels for spin current control. In some multi-functional perovskite materials, the RD effect coexists with ferroelectricity, where ferroelectric (FE) phase transitions can induce spin chirality reversal, presenting opportunities for spin-FET development.

We explore the effect of A cation (A = K, Rb, Cs, Tl) in spin-FET application of AIO₃ compounds via investigating the RD effect and FE properties. Our results demonstrate that smaller A-cation size leads to higher RD spin splitting, with KIO₃ exhibiting the most promising performance. Out of the four compounds studied, three show RD spin splitting of ±1 eV·˚A. Furthermore, we observe that FE phase transitions in all these compounds can influence the spin chirality. The FE switching barriers of all four compounds are below 1 eV/atom. These findings highlight the potential of AIO₃ compounds for spin-FET applications and suggest avenues for further optimization. Further, the presence of heavy element viz. Bismuth in BiMO₃ perovskites, offer potential platform for studying pronounced RD effect in bulk material. We explore the RD effect in experimentally synthesized non centrosymmetric phases of BiMO₃ (M = Al, Ga, In, Fe, Co, Sc, La). A comparative analysis indicates that, for compounds that stabilize in R3c phase, the Rashba splitting parameter is directly proportional to the extent of octahedral distortion, which in turn is largely dictated by the size of the M-cation.

Furthermore, the symmetry of the crystal structure plays a crucial role in determining the spin texture. Our study shows persistent spin texture in BiInO₃, which may find application in spin-charge inter-conversion. The exceptional Rashba activity in BiLaO₃ and BiScO₃ underscores their potential for spin-FET applications. In the final example, we study the RD effect in a more realistic SrGeO₃/KTaO₃ interface, and perform a regime-resolved analysis across the full valence–conduction band that identifies linear Rashba coefficients spanning to up to 2.35 eV·Å and thermally robust Rashba energies. Spin texture analysis confirms pure Rashba character driven by interfacial inversion symmetry breaking and Ta 5d orbitals. These findings establish germanate-based perovskite interfaces as a viable platform for high-mobility spintronics and gate-controlled spin manipulation.