Abstract: With a two-site Hubbard model and the Floquet theory,the dynamic behavior of excitons in coupled double quantum dots driven by DC-AC electric fields is investigated.The time-dependent Schrdinger equation is numerically solved,and Pmin,the minimum probability for the electron and the hole to remain in the initial localized state within 20 periods of the external field,is given.Results show that for a weak field,the exciton mainly oscillates between two localized states;however,for a strong field,the electron and the hole can independently tunnel between the two quantum dots.The driving field tends to drive the electron and the hole apart,and under appropriate conditions they can be localized in the initial state for a short time.The DC field breaks the dynamic symmetry of the system and affects the dynamic localization.

Key words: Floquet theory, quasi-energy, localized states, dynamical localization