Experimental evidence of t_2g electron-gas Rashba interaction induced by asymmetric orbital hybridization

We report the control of Rashba spin-orbit interaction by tuning asymmetric hybridization between Ti-orbitals at the LaAlO₃/SrTiO₃ interface. This asymmetric orbital hybridization is modulated by introducing a LaFeO₃ layer between LaAlO₃ and SrTiO₃, which alters the Ti-O lattice polarization and traps interfacial charge carriers, resulting in a large Rashba spin-orbit effect at the interface in the absence of an external bias. This observation is verified through high-resolution electron microscopy, magneto-transport and first-principles calculations. Our results open hitherto unexplored avenues of controlling Rashba interaction to design next-generation spin-orbitronics.