Spin-splitting of Aharonov–Bohm oscillations in an antidot

The conductance through a constriction containing an antidot often exhibits paired Aharonov–Bohm oscillations when the two spins of the lowest Landau level form quantised states. Peaks and dips of the resonances evolve in various ways as the magnetic field or the gate voltages are varied. We show that no existing models, which attribute each resonance to one or other spin, can explain the behaviour, implying the involvement of electron–electron interactions between states of opposite spin.