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.