DESIGN AND SIMULATION OF ARITHMETIC LOGIC UNIT USING QUANTUM DOT CELLULAR AUTOMATA

Quantum Dot Cellular Automata (QCA) is a modern paragon that encodes binary information, i.e. 0 and 1, inside a cell instead of traditional current switches. Information is expressed by a QCA cell's charging configuration. Current does not flow in these cells. This innovative concept provides a potential alternative to transistor-less computation at Nano scale. An ALU stands for Arithmetic Logic Unit which carries of logical and arithmetic operation based on the input operands. The concept of layering is used to give input to the proposed Arithmetic Logic Unit (ALU), thus reducing the occupation area and the cell count. It consists of Half Adder and NAND Gate followed by two 2x1 Multiplexer. The proposed design of half adder and NAND Gate (used for And operation) uses less occupation area, less number of cells and low energy dissipation than the existing designs