Observation of Zero-Dimensional States in a One-Dimensional Electron Interferometer

We have studied the electron transport in a one-dimensional electron interferometer. It consists of a disk-shaped two-dimensional electron gas, to which quantum point contacts are attached. Discrete zero-dimensional states are formed due to constructive interference of electron waves traveling along the circumference of the disk in one-dimensional magnetic edge channels. The conductance shows pronounced Aharonov-Bohm–type oscillations, with maxima occurring whenever the energy of a zero-dimensional state coincides with the Fermi energy. Good agreement with theory is found, taking energy averaging into account.