Study on Temperature Stability and Fault Tolerance of Adder in Quantum-dot Cellular Automata

Quantum-dot Cellular Automata (QCA) is the most sought after paradigms for designing layouts for digital circuits on a Nano-Scale. It has an edge over CMOS as the designs in QCA consume less power, are very small and their execution is very fast. QCA can perform computations which are dense in nature. It is being considered as a CMOS VLSI alternate. The cells in QCA transfer data based on their polarization state and the clock. For a real world implementation of QCA architecture it is crucial to know accurately about the limits on the operational environment for any given QCA design. The operation of any given QCA architecture will depend on many real world variables such as operational temperature, layer separation etc. This paper is an inference drawn from the study of a QCA design of Half Adder and Full Adder and its simulated operation under variable temperature. The study has been made on average energy dissipation, temperature stability along with fault tolerance under dislocation and vacancy of cells. The analysis is been made using QCADesignerE 2.0.3 simulation tool.