DIFFERENTIAL CHARGE DETECTION FOR QUANTUM-DOT CELLULAR-AUTOMATA

We report direct measurements of the charging diagram of a nanoscale s eries double-dot system at low temperatures. Our device consists of fo ur metal dots, with two of them in series forming a double-dot, and th e other two serving as electrometers for the double-dot system. This c onfiguration allows us to externally detect all possible charge transi tions within a double-dot system. Specifically, we can detect charge r edistribution in the double-dot, which corresponds to shift of an elec tron between two dots, using differential signal from the two electrom eters. We discuss possible applications as an output stage for quantum -dot cellular automata architecture. (C) 1997 American Vacuum Society.