Fundamental of Reversible Logic

Saleem Mohammed Ridha Taha

Anas N. Al‐Rabadi

Matthew A. Morrison, Nagarajan Ranganathan

Significant debate exists in the literature with regards to the permissibility of feedback in reversible computing nanotechnologies. Feedback allows for reuse of logical subroutines, which is a desired functionality of any computational device. Determining whether loop back is allowed is paramount to assessing the robustness of reversible logic in any quantum design. In this paper, the fundamental discoveries in entropy and quantum mechanics that serve as the foundations for reversible logic are reviewed. The fundamentals for implementation of reversibility in computing are shown. Then, definitions are presented for a sequential reversible logic structure. A sequential reversible logic structure is proven to have an identical number of feedback-dependent inputs and feedback-producing outputs, and new metrics for measuring the probability of each output state are presented. Using these metrics, the reversibility of each clock cycle of such a device is verified. Therefore, we demonstrate that any reversible logic structure with feedback is physically reversible.

P. Mercy Nesa Rani, Phrangboklang Lyngton Thangkhiew

One of the main motivations for using ternary logic systems is the amount of information per circuit line is higher as compared to the corresponding binary logic representation, thereby leading to more compact circuit realizations. This is particularly attractive for quantum computing as qutrits are expensive resources and minimizing their number is one of the main objectives during synthesis. Therefore, ternary reversible logic synthesis has drawn significant attention among researchers. It deals with fundamental unit of information called qutrits that can exist in one of the three states |0>, |1> and |2>. Hence, the aim of this paper is to bridge the knowledge gap for the beginners in this domain than searching the entire space. Therefore, the present work discusses the basic concepts of ternary reversible logic and ternary reversible gates. The detailed discussion of the various ternary reversible logic synthesis will enable the beginners in this domain to understand the ternary reversible logic in a better way.

Alexis De Vos, Leo Storme

Reversible logic plays a fundamental role both in ultra-low power electronics and in quantum computing. It is therefore important to know which reversible logic gates can be used as building block for the reversible implementation of an arbitrary boolean function and which cannot.

Ralph C. Merkle