Reversible Arithmetic Logic Gate (ALG) for Quantum Computation

At present, Boolean algebra based computations by the use of silicon based semiconductor technology are irreversible in nature. This is due to the mismatch of number of inputs and outputs. Reversible logic circuit maps unique input to the output and ensure one to one mapping and basis for emerging applications like low-power design, quantum computation, optical computing, bioinformatics and nanotechnologies. In computing paradigm, Arithmetic Logic Unit (ALU) is one of the computing intensive building blocks of the computer that performs arithmetic and logical operations. This work understands and nurtures the necessity of reversible ALU for future revolutionary computing technologies. In this paper, a 4x4 reversible gate which alone performs arithmetic and logic operations is proposed and compared with other reversible gates like TSG, HNG and MKG, in terms of quantum cost, I/O lines and Taffoli gates. The results of different synthesis methods of 4x4 ALG using Revkit tool are studied. Proposed gate performs better than existing methods and ensures maximum logical operations like full adder, full subtractor and all logical operations with less hardware cost where other existing gates are not viable.