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

Abstract

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 Ga 0.68In 0.32As 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.