Implementation of Quantum dot Cellular Automata based Novel Full Adder and Full Subtractor

Quantum-dot cellular automaton (QCA) is an up-coming nanotechnology in the area of nanoelectronics and is found to be an alternative solution to replace conventional CMOS technology for several reasons. It has attractive features such as faster speed, smaller size, and low power consumption compared to transistor-based technology. The experiments carried out in QCA demonstrated and realized the fundamental digital blocks. This paper demonstrates designing combinational circuits based on quantum-dot cellular automata (QCA), which covers a way to implement logic and all interconnections with homogeneous layer of cells. The novel implementation of full adder and full subtractor with less area, circuit complexity and clock delays are presented in this paper. Several full adders have been reported in literature but many other QCA based circuit implementations, including full subtractor, have not been reported in open literature. Comparative study illustrates significant improvements in our design as compared to traditional approaches. The correct logical functionalities of presented structures have been authenticated using QCADesigner tool.