Reversible Comparator Circuit Using a New Reversible Gate

Traditional electronics is ruling the digital world since long. Investigations have proved limitations of traditional electronics, and researchers are adopting new technologies to overcome these limitations. Quantum computing, nanotechnology, optical computing, low-power computing, etc. have become prominent fields of research in recent times. Reversible Logic is one of the emerging areas to this list to add. Quantum logic is reversible with very-low heat emission. This is one of the reasons why reversible logic and computing are turning popular areas of study and research. This paper presents a new reversible gate with its quantum representation. This gate can also be used to perform basic logical operations like OR, AND, NOT and XOR. This work also considers the design of digital comparators as they are widely used in arithmetic logic units, digital signal processors, etc. Single-bit comparators are designed using the proposed gate, and their performances are analyzed. Designs of multi-bit comparator circuits are also presented starting with a circuit for comparing two bits.