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

We report on the observation of ultra-high Aharonov–Bohm oscillations harmonics h / n e ( n = 40 – 45 ) in a very small quasibalistic ring (the ring effective radius is r = 60 – 75 nm ) fabricated on the basis of AlGaAs/GaAs heterostructures with a 2D electron gas. The highest harmonics observed so far were n = 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.