Tunable Two-Channel Magnetotransport in SrRuO3 Ultrathin Films Achieved by Controlling the Kinetics of Heterostructure Deposition

Abstract

In the field of oxide heterostructure engineering, there are extensive efforts tocouple the various functionalities of each material. The Berry curvature-drivenmagnetotransport of SrRuO3 ultrathin films is currently receiving a great dealof attention because it is extremely sensitive to the electronic structures nearthe Fermi surface driven by extensive physical parameters such as spin–orbitcoupling and inversion symmetry breaking. Although this is beneficial interms of heterostructure engineering, it renders transport behavior vulnerableto nanoscale inhomogeneity, resulting in artifacts called “hump anomalies.”Here, a method to tune the magnetotransport properties of SrRuO3 ultrathinfilms capped by LaAlO3 layers is developed. The kinetic process of pulsed laserdeposition by varying the growth pressure during LaAlO3 layer deposition issystematically controlled. Furthermore, the effects of nanoscale inhomogeneityon the Berry curvature near the Fermi surface in SrRuO3 films are investigated.It is found that the high kinetic energy of the capping layer adatoms inducesstoichiometric modification and nanoscale lattice deformation of the under-lying SrRuO3 layer. The control of kinetics provides a way to modulate mag-netization and the associated magnetotransport of the SrRuO3 layer.