Ultra-high Aharonov–Bohm oscillations harmonics in a small ring interferometer

We report on the observation of ultra-high Aharonov–Bohm oscillations harmonics h/neh/ne (n=40–45n=40–45) in a very small quasibalistic ring (the ring effective radius is r=60–75nm) fabricated on the basis of AlGaAs/GaAs heterostructures with a 2D electron gas. The highest harmonics observed so far were n=2–4n=2–4. The observation of harmonics of so high a frequency proves that in real scattering systems with dimensions of the order of the electron wave-length, multiple back-scattering processes are quite common.