The superconducting clock-circuit: Improving the coherence of Josephson radiation beyond the thermodynamic uncertainty relation

TL;DR

This paper introduces a superconducting clock circuit that surpasses the thermodynamic uncertainty relation to produce highly coherent Josephson radiation from a DC bias, advancing superconducting electronics.

Contribution

It demonstrates a novel superconducting clock circuit that breaks the TUR, enabling more coherent AC radiation emission from Josephson junctions.

Findings

Superconducting clock circuit emits more coherent Josephson radiation.

Violation of the TUR is achieved through the clock circuit design.

Enhanced coherence surpasses previous thermodynamic limits.

Abstract

In the field of superconducting electronics, the on-chip generation of AC radiation is essential for further advancements. Although a Josephson junction can emit AC radiation from a purely DC voltage bias, the coherence of this radiation is significantly limited by Johnson-Nyquist noise. We relate this limitation to the thermodynamic uncertainty relation (TUR) in the field of stochastic thermodynamics. Recent findings indicate that the thermodynamic uncertainty relation can be broken by a classical pendulum clock. We demonstrate how the violation of the TUR can be used as a design principle for radiation sources by showing that a superconducting clock circuit emits coherent AC radiation from a DC bias.