Phase-Tunable Thermal Logic: Computation with Heat

TL;DR

This paper introduces a novel thermal logic system using quantum effects in Josephson junctions to perform heat-based computation, potentially overcoming heat dissipation issues in miniaturized electronic devices.

Contribution

It proposes a new physical system for thermal logic operations, encoding logic states in temperature and utilizing quantum effects in Josephson junctions for dissipationless computation.

Findings

Thermal logic gates can be realized using Josephson junctions.

The proposed system operates at GHz frequencies with high stability.

It establishes a foundation for heat-based computation as an alternative to electronic logic.

Abstract

Boolean algebra, the branch of mathematics where variables can assume only true or false value, is the theoretical basis of classical computation. The analogy between Boolean operations and electronic switching circuits, highlighted by Shannon in 1938, paved the way to modern computation based on electronic devices. The grow of computational power of such devices, after an exciting exponential -Moore trend, is nowadays blocked by heat dissipation due to computational tasks, very demanding after the chips miniaturization. Heat is often a detrimental form of energy which increases the systems entropy decreasing the efficiency of logic operations. Here, we propose a physical system able to perform thermal logic operations by reversing the old heat-disorder epitome into a novel heat-order paradigm. We lay the foundations of heat computation by encoding logic state variables in temperature and introducing the thermal counterparts of electronic logic gates. Exploiting quantum effects in thermally biased Josephson junctions (JJs), we propound a possible realization of a functionally complete dissipationless logic. Our architecture ensures high operation stability and robustness with switching frequencies reaching the GHz.