Design and Analysis of a Fault Tolerant ۳-Input Majority Gate in Quantum-dot Cellular Automata

QCA is a kind of computational technology used for developing circuits in Nano sizes. Decreasing the dimensions of pieces has led to the increase of circuit sensibility and quantum circuits are more vulnerable to defects and radiations of the environment. Majority gate and NOT gate (inverter) are the two basic gates in QCA technology based on which almost all circuits are made. So far, a limited number of fault-tolerant majority gates have been presented and research in this particular field seems appropriate. In this research we intend to provide a comprehensive design of ۳-input majority gate in quantum cellular automata for all possible faults: misalignment, missing, dislocation, and redundancy so that low overhead is added to circuit. The gate is made up of both ۹۰-degree and ۴۵-degree cells. The results of this study indicate that our proposed ۳-input majority gate is more fault-tolerant to the defects compared to the formerly presented one.