Design of Fault-Tolerant and Thermally Stable XOR Gate in Quantum dot Cellular Automata

In this paper, a new XOR gate is discussed in quantum-dot cellular automata (QCA). The proposed gate is a single layer structure with no crossovers, and has been designed with redundant cells to increase the amplitude of the output signal and to improve the fault tolerance and reliability of the circuit. Based on the performance comparison, the investigated XOR gate has very high fault tolerance to single-cell addition and single-cell omission defects, thereby making them suitable candidates for designing reliable QCA based digital circuits.