DYNAMICS OF ELECTRONS IN A DOUBLE-QUANTUM DOT BIASED BY AN AC VOLTAGE- NONLINEAR EFFECT OF COULOMB INTERACTION

We investigate the dynamics of electrons in a double quantum dot biase d by an ac voltage. For a closed system with two electrons, the exact diagonalization is performed on a many-body basis with the help of the time-evolution operator. We find three singlet states which show diff erent dependences of quasienergies on the strength of Coulomb interact ion U. The amplitude, as well as the nonlinear features, of the oscill ation of the occupation number in a dot depends on the state and the v alue of U.