Bistable saturation in coupled quantum-dot cells

Model quantum dot cells are investigated as potential building blocks for quantum cellular automata architectures. Each cell holds a few electrons and interacts Coulombically with nearby cells. In acceptable cell designs, the charge density tends to align along one of two cell axes. Thus, a cell ‘‘polarization,’’ which can be used to encode binary information, is defined. The polarization of a cell is affected in a very nonlinear manner by the polarization of its neighbors. This interaction is quantified by calculating a cell–cell response function. Effects of nonzero temperature on the response of a model cell are investigated. The effects of multiple neighbors on a cell are examined and programmable logic gate structures based on these ideas are discussed.