Simulation of reversible molecular mechanical logic gates and circuits

TL;DR

This paper designs and simulates reversible molecular mechanical logic gates that operate near thermodynamic reversibility, enabling the construction of complex reversible circuits with minimal work costs.

Contribution

It introduces a novel design for molecular mechanical logic gates that are thermodynamically reversible and demonstrates how to build larger circuits like a half-adder using these components.

Findings

Isolated components operate reversibly under thermal noise

Reversible gates can be combined to form complex circuits

A working half-adder circuit was constructed and simulated

Abstract

Landauer's principle places a fundamental lower limit on the work required to perform a logically irreversible operation. Logically reversible gates provide a way to avoid these work costs, and also simplify the task of making the computation as a whole thermodynamically reversible. The inherent reversibility of mechanical logic gates would make them good candidates for the design of practical logically reversible computing systems if not for the relatively large size and mass of such systems. In this paper, we outline the design and simulation of reversible molecular mechanical logic gates that come close to the limits of thermodynamic reversibility even under the effects of thermal noise, and outline associated circuit components from which arbitrary combinatorial reversible circuits can be constructed and simulated. We demonstrate that isolated components can be operated in a thermodynamically reversible manner, and explore the complexities of combining components to implement more complex computations. Finally, we demonstrate a method to construct arbitrarily large reversible combinatorial circuits using multiple external controls and signal boosters with a working half-adder circuit.