A New Design for Two-input XOR Gate in Quantum-dot Cellular Automata

Quantum-dot Cellular Automata (QCA) technology is attractive due to its low power consumption, fast speed and small dimension, therefore, it is a promising alternative to CMOS technology. In QCA, configuration of charges plays the role which is played by current in CMOS. This replacement provides the significant advantages. Additionally, exclusive-or (XOR) gate is a useful building block in many important circuits such as full adder (FA). In this paper we propose a novel design for two-input XOR gate in QCA. Two-input XORs could be utilized in constructing three-input ones which are widely used. The proposed XOR gate is the smallest design among the two-input XORs and it achieves significant improvements in terms of complexity and latency in comparison to the only existing similarly designed gate. Contrary to the common designing method which uses the logic function of XOR, the gate is constructed based on explicit interactions between QCA cells. The simulation results have been verified using the QCADesigner.