  We investigate the dynamics of interacting electrons confined to two types of
quantum dot system, when driven by an external AC field. We first consider a
system of two electrons confined to a pair of coupled quantum dots by using an
effective two-site model of Hubbard-type. Numerically integrating the
Schroedinger equation in time reveals that for certain values of the strength
and frequency of the field the tunneling between the dots can be destroyed,
thus allowing the correlated two-electron states to be manipulated. We then
show how Floquet theory can be used to predict the field parameters at which
this effect occurs. We then consider the case of confining the electrons to a
single two-dimensional quantum dot in the limit of low particle-density. In
this system the electrons form strongly correlated states termed Wigner
molecules, in which the Coulomb interaction causes them to become highly
localised in space. Again using an effective model of Hubbard-type, we
investigate how the AC field can drive the dynamics of the Wigner states. As
before, we find that the AC field can be used to control the tunneling between
various charge configurations, and we relate this to the presence of avoided
crossings in the Floquet quasi-energy spectrum. These results hold out the
exciting possibility of using AC fields to control the time evolution of
entangled states in mesoscopic devices, which has great relevance to the
rapidly advancing field of quantum information processing.
