  The many-body state of carriers confined in a quantum dot is controlled by
the balance between their kinetic energy and their Coulomb correlation. In
coupled quantum dots, both can be tuned by varying the inter-dot tunneling and
interactions. Using a theoretical approach based on the diagonalization of the
exact Hamiltonian, we show that transitions between different quantum phases
can be induced through inter-dot coupling both for a system of few electrons
(or holes) and for aggregates of electrons and holes. We discuss their
manifestations in addition energy spectra (accessible through capacitance or
transport experiments) and optical spectra.

Mesoscale and Nanoscale Physics;Strongly Correlated Electrons