Tailoring large magnetoresistance in Dirac semimetal SrIrO3 films

Abstract

Perovskite SrIrO3 is a special Dirac material with fascinating effects due to its strong electron correlation and spin-orbit coupling. In this work, a large magnetoresistance (MR) was observed not only in epitaxial SrIrO3 films but also in a SrIrO3/PbZr0.2Ti0.8O3 epitaxial heterostructure with a magnetic field applied perpendicular to the external electric field. The magnetoresistance of SrIrO3 (10 nm) and SrIrO3/PbZr0.2Ti0.8O3 (10 nm/30 nm) reach values as large as 40% and 110% at 9 T and 5 K, respectively. We believe that the unusual magnetoresistance is from the Dirac/Weyl state. Especially, the SrIrO3/PbZr0.2Ti0.8O3 bilayer shows negative magnetoresistance with strong oscillations close to the angle positions, where the magnetic field is parallel to the electric field at 1.8 K, which arises from the chiral anomaly. Based on first-principle calculations and study, the polarization field of PbZr0.2Ti0.8O3 can modulate the band structure of SrIrO3, which can modify the MR of SrIrO3. The SrIrO3/PbZr0.2Ti0.8O3 heterostructure accommodating both the ferroelectric property and the Dirac/Weyl state may open the avenue to manipulate the Dirac/Weyl properties via the electric polarization field.