Localization effect in mesoscopic quantum dots and quantum-dot arrays

We discuss the observation of an unusual type of localization in split-gate quantum dots and quantum-dot arrays. While no evidence for its existence i s found prior to biasing the gates, the localization persists to conductanc e values as high as 50 e(2)/h and is not destroyed by the application of a weak magnetic field. The carrier density in the dots remains constant over the range of gate bias studied and these characteristics suggest that the l ocalization is quite distinct to that studied previously in two-dimensional semiconductors. We suggest that a confinement-induced enhancement of the e lectron-electron interaction may be responsible for the localization and pr opose a simple functional form which allows us to account for its variation as a function of either temperature or source-drain voltage. [S0163-1829(9 9)52848-8].