Analytical study of absorption threshold frequency of tuned quantum dot/ring system

In the present work, a tuned quantum dot/ring system under an external magnetic field is studied. Analytical methods are used to derive the wave functions and energy eigenvalues. The interband light absorption coefficient is then calculated analytically. Additionally, an analytical relationship is derived for the absorption threshold frequency (ATF) of the system. It is observed using those analytical formulas that: i) The ATF behaves differently for large and small magnetic fields. ii) The ATF increases as the magnetic field is increased and decreases as system size is increased. iii) The ATF can be increased by enhancing the repulsive potential of the system. Our results show that the model can be transformed into either a 2D quantum disk or ring, offering the possibility of using our findings about the absorption coefficient and ATF in photodetectors based on 2D quantum dots.