Universal programmable logic gate based on quantum-dot cellular automata for enhancing reliability and efficiency of digital systems

• A more detailed description of the QCA cell has been provided. • A detailed description of polarization due to changes in the QCA clock has been provided. • A description of the parameters of the two simulation engines has been added. • A description of the simulation results has been added. • An explanation of the relationship between quantum computing and the QCA universal gate has been added. As quantum-dot cellular automata (QCA) is gaining attention as a next-generation circuit technology, various logic circuits using QCA are being developed. The performance of digital logic circuits depends on the performance of basic logic gates, and the development of efficient universal gates improves the reliability and efficiency of digital systems by reducing the types of basic logic gates. This study proposes an efficient QCA-based universal programmable logic (UPL) gate that can perform not only NAND and NOR, which are well-known as universal gates, but also XOR and XNOR, which have complex structures of 2-level logic gates, with a single gate. A variety of combinational logic circuits are designed using the proposed UPL gate, and it is demonstrated that it operates as a universal gate and is scalable. Furthermore, the average output polarization is highly stable, exceeding 9.5, and it demonstrates a significant 44% improvement in design cost compared to the best existing QCA-based universal gate. These efforts ultimately lead to the simplification of the design and process of digital systems, which reduces the number of points of failure and reduces the manufacturing cost.