Revealing the complex band structure of LAO/STO interface by high magnetic field quantum transport

The transport properties of LAO/STO interface were investigated under high magnetic field. We observe oscillations of the magneto-resistance with altered periodicity when plotted versus inverse magnetic field. This effect can be linked to the Rashba spin-orbit coupling and remains consistent with large negative magneto-resistance when the field is parallel to the sample’s plane. The gate dependent data at very low temperature (down to 40 mK) show a richer Shubnikov de-Haas oscillations in the longitudinal magneto-resistance RXX(B) with several frequencies in the FFT (Fast Fourier Transform) spectrum. From the gate dependant results, we infer the presence of many sub-bands involved in the quantum transport properties, yielding a complex Landau Level diagram.

In collaboration with M. Pierre, T. Venkatesan, J. M. D. Coey, D. Maude