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

In the field of oxide heterostructure engineering, there are extensive efforts to couple the various functionalities of each material. The Berry curvature-driven magnetotransport of SrRuO3 ultrathin films is currently receiving a great deal of attention because it is extremely sensitive to the electronic structures near the Fermi surface driven by extensive physical parameters such as spin-orbit coupling and inversion symmetry breaking. Although this is beneficial in terms of heterostructure engineering, it renders transport behavior vulnerable to nanoscale inhomogeneity, resulting in artifacts called "hump anomalies." Here, a method to tune the magnetotransport properties of SrRuO3 ultrathin films capped by LaAlO3 layers is developed. The kinetic process of pulsed laser deposition by varying the growth pressure during LaAlO3 layer deposition is systematically controlled. Furthermore, the effects of nanoscale inhomogeneity on 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 induces stoichiometric modification and nanoscale lattice deformation of the underlying SrRuO3 layer. The control of kinetics provides a way to modulate magnetization and the associated magnetotransport of the SrRuO3 layer.