Quantum longitudinal and Hall transport at the LaAlO3/SrTiO3 interface at low electron densities

• We observed novel plateaus in the Hall conductivity at the LaAlO3/SrTiO3 interface.
• The Landau indices of the Hall plateaus have an interval close to 4.
• The frequency of quantum oscillations has a sharp transition with magnetic field.
• These features can be understood by considering magnetic breakdown orbits.

We examined the magneto-transport behavior of electrons confined at the conducting LaAlO3/SrTiO3 interface in the low sheet carrier density regime. We observed well-resolved Shubnikov-de Haas quantum oscillations in the longitudinal resistance, and plateau-like structures in the Hall conductivity. The Landau indices of the plateaus in the Hall conductivity data show spacing close to 4, in units of the quantum of conductance. These experimental features can be explained by a magnetic breakdown transition, which quantitatively explains the area, structure, and degeneracy of the measured Fermi surface.