Abstract

Nano-fabrication technology allows us to manipulate quantum states in various systems. Recently NTT group succeeded the manipulation of an electronic state in quantum-dots arrays. Motivated by this experiment, a novel method to manipulate the electronic state in quantum-dots is proposed utilizing the theory of nonadiabatic transition. The general condition for the coherent manipulation is derived employing the transfer matrix formalism for the Landau-Zener mechanism. This method is applicable to any discrete-level systems. The nonadiabatic manipulation extends the variation of experimental technique for a coherent manipulation. We also consider the application of the theory to related transport phenomena under time varying voltage in quantum dots and to spin entangled current in triple-dots system. These transport phenomena will be observed in experiments.