Manipulating Spin-Orbit Coupling at Oxide Interfaces by Lanthanum Cobaltate

The two-dimensional electron gas at the interfaces of insulating oxides has been one of the hot issues contributing to the development of all-oxide devices. The introduced buffer layer at interfaces will produce some strange physical properties due to the broken space-reversal symmetry. Here, we investigate the electronic transport property at heterointerfaces by introducing buffer layers of lanthanum cobaltate with different thicknesses. It is found that the interfaces show a metal-to-insulator transition, and the mobility is enhanced by more than 1 order of magnitude upon increasing the thickness. More importantly, two types of carriers at the interfaces are observed, simultaneously accompanied by the spin-orbit coupling effect, which can be attributed to the occupation of the 3d-orbit band of carriers. These results show that the buffered materials at interfaces can be designed to tune the spin-orbit coupling effect and lay a foundation for further applications of oxide spintronic devices.