Unified Reversible logic gate for Half Add/Subtract and Swap Operations

The reversible logic gates are the most eminent enabled technology for energy efficient system realization. This paper introduced a unified reversible logic gate called HAS
²
gate for performing arithmetic addition/subtraction and swap operations. The designed gate can also perform other Boolean functions as copy, NOT, AND, Exclusive-OR and Exclusive-NOR. The proposed gate is compared with other existing gates regarding quantum cost, garbage values and count of reversible gates.