LAUSR

Quantum-dot cellular automata (QCA), one of the alternative CMOS technologies at a nano scale, promises to design digital circuits with extra low-power, extremely dense and high speed structures. In this paper, a new QCA gate with three inputs and two outputs is first introduced; this operates on the basis of cell interactions. Then, low complexity and high-speed QCA full-adder and full-subtractor structures are proposed by applying different formulations, which are based on the introduced gate. Finally, a novel QCA full adder/subtractor is presented with the synergy of the proposed QCA full-adder and full-subtractor structures as well as a proposed optimal single layer 2:1 QCA multiplexer. The proposed designs are simulated using the QCA Designer 2.0.3. The simulation results confirm that the proposed circuits work well. A comparative analysis indicates the superiority of the proposed designs compared to the other related designs. Moreover, the QCAPro power estimator tool is utilized to evaluate the power dissipation of the proposed designs.