Strong Rashba parameter of two-dimensional electron gas at CaZrO/SrTiO heterointerface.

We synthesized a CaZrO/SrTiO oxide heterostructure, which can serve as an alternative to LaAlO/SrTiO, and confirmed the generation of 2-dimensional electron gas (2-DEG) at the heterointerface. We analyzed the electrical-transport properties of the 2-DEG to elucidate its intrinsic characteristics. Based on the magnetic field dependence of resistance at 2 K, which exhibited Weak Anti-localization (WAL) behaviors, the fitted Rashba parameter values were found to be about 12-15 × 10 eV*m. These values are stronger than the previous reported Rashba parameters obtained from the 2-DEGs in other heterostructure systems and several layered 2D materials. The observed strong spin-orbit coupling (SOC) is attributed to the strong internal electric field generated by the lattice mismatch between the CaZrO layer and SrTiO substrate. This pioneering strong SOC of the 2-DEG at the CaZrO/SrTiO heterointerface may play a pivotal role in the developing future metal oxide-based quantum nanoelectronics devices.