Reversible Comparator Design Using Quantum Dot-Cellular Automata
Jadav Chandra Das, Debashis De · IETE Journal of Research · 2015
Quantum dot-cellular automata (QCA) emerge as a research area to design nanometre scale logic circuit. In digital logic design, a comparator is the fundamental building block that performs the comparison of two numbers. This paper deals with the design of reversible building block for 1-bit comparator and its implementation in QCA. An improved QCA layout of Feynman gate is also achieved. The QCA Feynman gate is denser and has low delay than the existing circuit. The proposed reversible comparator has quantum cost 9, whereas the QCA reversible comparator has the quantum cost 0.927. The quantum cost based comparison of the proposed QCA reversible comparator with conventional reversible comparator shows the cost effective circuit design in QCA. The simulation result matched the truth table of comparator which approves the functional capability of the proposed QCA layout of comparator. All the proposed layouts dissipate very low power.