AC-stark effect in a semi-spherical quantum dot

We present a theoretical approach to study the effects of an ac-field applied to quantum dots with semi-spherical symmetry. Using the Floquet formalism for this periodically driven system, the time-dependent Hamiltonian in the effective mass approximation is solved. We show that the Hilbert space of solutions is separated into orthogonal subspaces with different z-component of the angular momentum. We give an explicit analytical representation for electronic states as a function of the intensity and frequency of the electric field. Under the two level approximation, two particular cases are studied: the low- and high-frequency regimes, which result of comparing the ac-field frequency to the characteristic level splitting at zero field. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.