Low magnetic field effect on the polarisability of excitons in spherical quantum dots

We present a theoretical study of the simultaneous effects of magnetic and electric fields on the ground state energy of an exciton confined in US and CdSSe spherical quantum dots. The effect of the quantum confinement is des cribed by an infinitely deep potential well in the framework of the effecti ve mass approximation. The effects of the external perturbations are treate d within the Hasse variational method. The variations of the diamagnetic co efficient D are determined as a function of the dot radius R. The influence of the quantum confinement and the magnetic field strength on the excitoni c polarisability x is analysed.