Electronic coupling of vertically coupled quantum dots: effect of the time-dependent magnetic field

The fast development of the new classes nanostructures such as self-organized quantum dots leads to the possibility of controlling their shape, their dimensions, the structure of energy levels and the number of confined electrons (from one to 1000). A fascinating idea of great promise is the possibility of utilizing electronic spins in semiconductor quantum dots as quantum bits (qubits) for a new generation of computers. In this work, we consider two vertically Ga0.68In0.32As coupled-quantum dots embedded in GaAs. We study the dynamical response of two electrons in these two vertically tunnel-coupled quantum dots with a time dependent magnetic field and including the Coulomb interaction between the electrons. We find that, for a certain frequency ranges, a sinusoidal perturbation acts like an attractive effective interaction between electrons. Including the Zeeman splitting on the spins of the electrons we discuss the dynamical evolution of the magnetization, (C) 2002 Elsevier Science B.V. All rights reserved.