Quaternary Quantum/Reversible Half-Adder, Full-Adder, Parallel Adder and Parallel Adder/Subtractor Circuits

Multiple valued quantum logic is a promising research area in quantum computing technology having several advantages over binary quantum logic. Adder circuits as well as subtractor circuits are the major components of various computational units in computers and other complex computational systems. In this paper, we propose a quaternary quantum reversible half-adder circuit using quaternary 1-qudit gates, 2-qudit Feynman and Muthukrishnan-Stroud gates. Then we propose a quaternary quantum reversible full adder and a quaternary quantum parallel adder circuit. In addition, we propose a quaternary quantum reversible parallel adder/subtractor circuit. The proposed designs are compared with existing designs and improvements in terms of hardware complexity, quantum cost, number of constant inputs and garbage outputs are reported.