Evidence for a reentrant metal-insulator transition in quantum-dot arrays

We present evidence for gate voltage-induced localization, and a possibly r e-entrant metal-insulator transition, in linear quantum dot arrays that are realized using the split-gate technique. No evidence for the localization is observed prior to biasing the gates of the array, and the details of thi s behavior are found to be strongly device dependent. The metal-insulator t ransition is thought to arise as the gate voltage sweeps the discrete level spectrum of the array past the Fermi surface, mapping out regions of local ized and extended states. In the metallic regime, the resistance varies log arithmically with temperature, behavior which is not seen in the underlying two-dimensional electron gas, but which is consistent with recent predicti ons for a correlated electron liquid. [S0163-1829(99)15747-3].