The excitation spectrum of quantum antidots

Source-drain bias measurements of transport across quantum antidots reveal a ladder of excited states analogous to the excitation spectrum of quantum dots. The antidot excitation spectrum provides an unambiguous method of determining the Coulomb-blockade charging energy and the energy difference between antidot single-particle states. The energy-level spacings and the presence of strong Kondo resonances in this regime cannot be explained within a non-interacting model.