Enhanced tunneling magnetoresistance and spin filtering in perovskite magnetic tunnel junctions via oxygen octahedral tilting

Oxygen octahedral tilting significantly reduces the symmetry of perovskites and changes transport properties perovskite magnetic tunnel junctions (MTJs). We investigated ${\mathrm{SrRuO}}_{3}/{\mathrm{CaTiO}}_{3}/{\mathrm{SrRuO}}_{3}$ MTJs by first-principles simulation predicted an intriguing coupling between oxygen tunneling magnetoresistance. obtained higher spin polarization at Fermi level for ${\mathrm{SrRuO}}_{3}$ electrodes with tilted octahedra, which increases magnetoresistance value. Transmission complex band structure analysis shows that majority current in ${\mathrm{CaTiO}}_{3}$ barrier octahedra is suppressed wave function filtering, thus producing a negative filtering efficiency close to \ensuremath{-}100% further enhancing TMR effect. Both phenomena disappear junction without tilting, hence they have resulted from lattice distortions. The effective control via could act as way improve performances spintronic devices.