Towards Practical Reversible Logic

Naoki Takeuchi, Yuki Yamanashi, Nobuyuki Yoshikawa

Reversible computing has been studied since Rolf Landauer advanced the argument that has come to be known as Landauer's principle. This principle states that there is no minimum energy dissipation for logic operations in reversible computing, because it is not accompanied by reductions in information entropy. However, until now, no practical reversible logic gates have been demonstrated. One of the problems is that reversible logic gates must be built by using extremely energy-efficient logic devices. Another difficulty is that reversible logic gates must be both logically and physically reversible. Here we propose the first practical reversible logic gate using adiabatic superconducting devices and experimentally demonstrate the logical and physical reversibility of the gate. Additionally, we estimate the energy dissipation of the gate, and discuss the minimum energy dissipation required for reversible logic operations. It is expected that the results of this study will enable reversible computing to move from the theoretical stage into practical usage.

Trailokya Nath Sasamal, Ashutosh Kumar Singh, Anand Mohan

Hari Mohan Gaur, Trailokya Nath Sasamal, Ashutosh Kumar Singh +2 more

Erik P. DeBenedictis

This paper is about making reversible logic a reality for supercomputing. Reversible logic offers a way to exceed certain basic limits on the performance of computers, yet a powerful case will have to be made to justify its substantial development expense. This paper explores the limits of current, irreversible logic for supercomputers, thus forming a threshold above which reversible logic is the only solution. Problems above this threshold are discussed, with the science and mitigation of global warming being discussed in detail. To further develop the idea of using reversible logic in supercomputing, a design for a 1 Zettaflops supercomputer as required for addressing global climate warming is presented. However, to create such a design requires deviations from the mainstream of both the software for climate simulation and research directions of reversible logic. These deviations provide direction on how to make reversible logic practical

Kalyan S. Perumalla

Historically, logic gates have been used as building blocks for theoretical development of deterministic computation, and the assembled logic is realized in practice over physical processes such as composition of variable voltage levels in electronic circuit elements. However, much of the logic gate theory and design has focused on forward computation only, without explicit consideration of reversible execution. Here, we consider the reversibility aspect of traditional 2-bit gates and describe the concepts behind the development of reversible gates (which happen to require gates with at least 3 bit-wide inputs and outputs), and describe popular 3-bit reversible logic gates.

Anas N. Al‐Rabadi