A novel single layer full-adder in Quantum-dot Cellular Automata (QCA) 

Quantum-dot Cellular Automata (QCA) is a new technology for designing digital circuits in nanoscale. The design of a QCA circuit is radically different from the conventional digital design due to its unique characteristics at both the physical and logical levels. Quantum-dot Cellular Automata is not a physical implementation yet, it is rather a lower-level abstraction since there are several ways to build the quantum dots and connect them. Quantum dots can be any charge containers, with discrete electrical energy states (there may be more than two states, but only two-state case is used), sometimes called artificial atoms. In this paper, a new 3-input majority gate was initially proposed, then an efficient design of a single-layer full-adder was introduced using the proposed optimized 3-input majority gate. The functional correctness of the proposed structure is evaluated by the QCA Designer tool. Simulation results show that the proposed full-adder is improved and more efficient in terms of area, the number of cells, and latency.