Digital logic gate using quantum-dot cellular automata

Abstract

A functioning logic gate based on quantum-dot cellular automata is presented, where digital data are encoded in the positions of only two electrons. The logic gate consists of a cell, composed of four dots connected in a ring by tunnel junctions, and two single-dot electrometers. The device is operated by applying inputs to the gates of the cell. The logic AND and OR operations are veriÞed using the electrometer outputs. Theoretical simulations of the logic gate output characteristics are in excellent agreement with experiment. Field-effect transistors (FETs) are the founda-tion of present digital logic technologies such as complementary metal oxide semiconductors. Despite vast improvements in integrated circuit fabrication technology over the past three de-cades, the role played by the FET has remained that of a current switch, much like the mechan-ical relays used by Konrad Zuse in the 1930s