Aharonov–Bohm oscillations in p-type GaAs quantum rings

We have explored phase coherent transport of holes in two p-type GaAs quantum rings with orbital radii 420 and 160 nm fabricated with AFM oxidation lithography. Highly visible Aharonov–Bohm (AB) oscillations are measured in both rings, with an amplitude of the oscillations exceeding 10% of the total resistance in the case of the ring with a radius of 160 nm. Beside the h/e oscillations, we resolve the contributions from higher harmonics of the AB oscillations. The observation of a local resistance minimum at View the MathML source in both rings is a signature of the destructive interference of the holes’ spins. We show that this minimum is related to the minimum in the h/2e oscillations.