QCA circuit design based on novel optimal ULG.2

Quantum-dot cellular automata (QCA) is a promising nanotechnology, with the potential for faster speed, smaller size and lower power consumption than CMOS technology. In QCA circuit design, However, wire-crossing is an issue. Universal logic gates (ULG) have stronger function than traditional logic gates. This paper begins with a review of QCA. Then a novel QCA optimal ULG.2 is obtained using a new algorithm and modular design methodology. Some circuits are implemented with the ULG.2. As an example, finally, a full adder/subtraction is constructed by applying the ULG.2. The simulation results confirm that all the proposed circuits not only hold correct logic function but also achieve a considerable wire-crossing count reduction in comparison to the other previous designs.