A new fault-tolerant single-bit comparator in QCA technology using a novel X-NOR gate

Quantum-dot Cellular Automata (QCA) is one of the potential remedies to the limitations of transistor-based technologies. The QCA is brand-new, significant nanotechnology that has caught the attention of many scholars. It has a lot of tempting qualities, such as quick speed, low energy usage, and small size. This work uses QCA's cell contact rules to provide a new fault-tolerant XNOR gate. Additionally, a unique comparator circuit is suggested that makes use of the fault-tolerant XNOR gates. The proposed comparator offers a noteworthy improvement in both area and gate count. The proposed circuits' functionality, implementation, and testing are validated using the QCADesigner simulator. Only 106 cells make up this fault-tolerant comparator, which has a desirable size of 0.10 µm2. Additionally, the outcomes showed that the design offers improved fault-tolerant features in comparison to its alternatives. Investigations also looked into single-cell omission, displacement, misalignment, and other deposition defects. Based on the experiment's outcomes, the suggested comparator can tolerate more than 80 % of faults.