CORRELATED CHARGE POLARIZATION IN A CHAIN OF COUPLED QUANTUM DOTS

Coherent charge transfer in a linear array of tunnel-coupled quantum d ots, electrostatically coupled to external gates, is investigated usin g the Bethe ansatz for a symmetrically biased Hubbard chain. Charge po larization in this correlated system is shown to proceed via two disti nct processes: formation of bound states in the metallic phase, and ch arge-transfer processes corresponding to a superposition of antibound states at opposite ends of the chain in the Mott-insulating phase. The polarizability in the insulating phase of the chain exhibits a univer sal scaling behavior, while the polarization charge in the metallic ph ase of the model is shown to be quantized in units of e/2.