CSWAP Operator as 2×1 Multiplexer to Design CNOT and CCNOT Gates based Carry Select Adder
R Maheswari, S Shaistha, U Sravani, V Monika, Enaul Haq Shaik · 2021 International Conference on Communication, Control and Information Sciences (ICCISc) · 2021
Quantum computing is emerging as an alternative to the classical computer, based on the fundamental properties of quantum physics. This leads to develop quantum systems to solve complex problems which a classical system is unable to do. In this article, we propose the design of adders using low quantum cost full adder. Initially, full adder is proposed using CNOT and CCNOT gates, and later parallel adder and carry select adder are designed using it. Apart from full adder, additional gates are not required to design parallel adder while CSWAP gates are utilized to propose carry select adder. CSWAP gate is modeled as 2×1 multiplexer and used to select the output from any one among the two parallel adders that constitutes carry select adder. An open source IBM Qiskit tool is used to design and simulate the adder circuits and observed the metrics.