Design of 2's Complement of 4-Bit Binary Numbers Using Quantum Dot Cellular Automata

Quantum Dot Cellular Automata is an emerging field in the domain of nanotechnology where circuits are designed in the nano level which are compatible to the circuits designed in traditional CMOS technology. Quantum Dot Cellular Automata gives a new dimension of ideas of designing basic gates in digital electronics with minimum hardware complexity. Transistor based CMOS designing faces many challenges due to the device dimension and leakage current but in QCA, quantum cells are in nano scale that contains quantum dots which help to transfer the information without any leakage current. This paper has demonstrated the design of 2' Complement of 4-bit binary numbers using layered and majority gate based Quantum Dot Cellular Automata. The calculation of kink energy has determined the stability of the circuit. The simulation results have been generated and verified using the QCA Designer tool.