Quantum-dot Cellular Automata (QCA) represents a new technology at the nanotechnology level. Conventional digital technologies use ranges of voltage or current to represent binary values. In contrast, QCA uses the positions of electrons in quantum dots to represent binary Values '0' and '1'. Quantum technology has gradually applied in various fields. A quantum-dot cellular automaton is projected as a promising nanotechnology for future ICs. A QCA is an array of structures known as quantum-dots. The advantages of using QCA technology are smaller circuit size, higher clock frequency, and lower power consumption.