Aharonov-Bohm Oscillations in the Exciton Luminescence from a Semiconductor Nanoring

Magnetoluminescence of an exciton confined within a semiconductor ring is studied theoretically. We demonstrate that, despite the net electrical neutrality of the exciton, both the spectral position and the intensity of the photoluminescence peak exhibit periodic oscillations as a function of magnetic flux threading the ring. The period of oscillations is Φ0 — the universal flux quantum. The origin of the effect is the finite probability for bound electron and hole to tunnel in the opposite directions and meet each other on the opposite side of the ring.