Prediction of a spin-polarized two-dimensional electron gas at the LaAlO3/EuO(001) interface

First-principles calculations predict the existence of a spin-polarized two-dimensional electron gas (2DEG) at the LaO/EuO interface in a LaAlO3/EuO(001) heterostructure. This polar interface favors electron doping into the Eu-5d conduction bands resulting in a 2DEG formed at the interface. Due to the exchange splitting of the Eu-5d states, the 2DEG is spin polarized below the Curie temperature of EuO. The predicted mechanism for the formation of a spin-polarized 2DEG at the interface between polar and ferromagnetic insulators may provide a robust magnetism of the 2DEG which is interesting for spintronics applications.