The effect of quantum ring size on shifting the absorption coefficient from infrared region to ultraviolet region

In this paper, the effects of magnetic flux and the width of the quantum ring on plasmon frequency are studied in a narrow quantum ring threaded by magnetic flux. Plasmon frequency is obtained by random phase approximation in the zero wave vector limits. Calculation of plasmon frequency as a function of magnetic flux shows Aharonov-Bohm oscillations. The periodicity and the amplitude of Aharonov-Bohm oscillations depend on magnetic flux and the width of the ring. In other words, the plasmon frequency of the quantum ring is sensitive to the variation of the magnetic flux and when the width is small, the modulation is more sensitive since the period and amplitude are smaller. The absorption coefficient versus ring radius changes from infrared region to ultraviolet region, which it can be of relevant application in solar cells.