Quantum Cost-Efficient Design of Synchronous Reversible Shift Registers using Reversible Logic

Reversible circuits are one of the most promising technologies for replicating inputs from recorded outputs, and it results in lower power dissipation. All gates such as NAND, AND, OR, NOR etc. are irreversible in nature and consume energy during calculations. Similar to quantum circuits, reversible logic circuitry does not consume energy throughout the calculation cycle. Due to this, reversible circuits can be used for quantum communication and other low-power applications. Registers are one of the most important storage components utilised in a wide range of real-time operations. Using expressions of exclusive-or sum of products (ESOP) and modified Fredkin gates, this work presents a novel way for creating a quantum cost-effective universal register circuit. The designed universal register circuitry for left and right shifts are tested in the Xilinx Vivado simulator to ensure that they are functional and logically correct. The proposed universal registers outperform the standard designs in terms of garbage outputs (GO), quantum cost (QC), gate count (GC), and Ancilla inputs (AI), according to the comparative analysis.