Optical aharonov-bohm effect in type-II (ZnMn)Te/ZnSe quantum dots

Photoluminescence for type-II, II-VI Zn(SeTe) quantum dots (QDs) in ZnTe/ZnSe superlattice demonstrate large and persistent oscillations in the energy and intensity indicating the presence of coherently rotating correlated electron-hole states, and the existence of the optical Aharonov-Bohm effect. The magnitude of the effects observed is attributed to the unique geometry of the columnar type-II structures investigated, which creates a natural ring-like geometry. The potential of this geometry to favor the optical AB effect is further demonstrated in similar (ZnMn)Te QD structures. Interestingly, in these magnetic dots the strength of the Aharonov-Bohm coherence is extremely sensitive to the magnetic properties of the dots, which can be enhanced or destroyed according to the spin disorder in the system. This effect is related to the strong exchange interaction between the rotating carrier and the Mn-ions In the dots. In addition, the magnetic nature and type-II band alignment of these QDs results in the formation of robust magnetic polarons, evidence of which persists until >150 K.