Magnetic Freezing Effect for the Ground State of Quantum Dot
  Within the framework of zero-range potential model in the ap-proach of effective mass, the impurity absorption by the complex Quantum Dot-Impurity Center in an external constant uniform magnetic field is considered. Under condition that the influence of a magnetic field on the ground state of quantum dot is negligible, we have derived the light absorption coefficient of impurity for the case of longitudinal polarization. It is shown that with an increase of the intensity of magnetic field the threshold of an impurity absorption band is shifted to the short-wave spectrum region. Also, the absorption coefficient increases by several times that can be explained as a result of the "magnetic freezing" effect for the ground state of quantum dot. 
V. D. Krevchik, A. B. Grunin, A. K. Aringazin, and M. B. Semenov