Observation of Shubnikov–de Haas Oscillations, Planar Hall Effect, and Anisotropic Magnetoresistance at the Conducting Interface of EuO–KTaO3

The momentum-dependent splitting of spin-bands in an electronic system is known as the “Rashba effect.” Systems with the Rashba effect possess a Dirac point in momentum space, which may act as a source of Berry's phase for the conduction electrons of such system. Herein, the Shubnikov–de Haas oscillations (SdH) at the conducting interface of EuO–KTaO3 (KTO) are reported. The observed SdH oscillations suggest the presence of two Fermi surfaces. For both Fermi surfaces, the presence of a Berry's phase is seen. Strong spin–orbit coupling is also observed in this system. The existence of two Fermi surfaces with Berry's phase along with the signature of strong spin–orbit coupling suggest the formation of Rashba spin-split bands. As in topological insulators, two-fold planar Hall effect and anisotropic magnetoresistance are also observed in EuO–KTO. Analyzing the SdH, Hall, and magnetoresistance data, the authors draw a possible band diagram near the Fermi surface.