Oscillatory persistent currents in nano-volcanoes

Using an ultra sensitive torque magnetometer we performed magnetic moment measurements on a sample containing 29 layers of self‐assembled InAs/GaAs quantum rings. These strongly non‐ideal rings, in fact they more resembling nano‐volcanoes, show a surprisingly high magnetic moment signal corresponding to a single electron persistent current of about 0.2μA. The predictions of our theoretical model, based solely on X‐STM measurements, is in good agreement with our experiments.