Breakdown of Shubnikov-de Haas oscillations in a short-period 1D lateral superlattice

Magnetic breakdown is observed in a two-dimensional electron system subject to a strong, atomically precise, one-dimensional potential with a period of 15 nm. The transition from closed to open electron orbits is studied in magneto-transport experiments by continuously changing the Fermi energy of the superlattice within and above the first miniband. Shubnikov-de Haas oscillations quench for Fermi energies close to the miniband gap but recover at higher magnetic fields. The density of states is clearly altered from a conventional 2D system which manifests itself in aperiodic magnetooscillations when sweeping the Fermi energy at fixed magnetic fields.