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

• Published in: SciPost physics Vol. 17; no. 5; p. 140
• Main Authors: Scheer, David, Völler, Jonas, Hassler, Fabian
• Format: Journal Article
• Language: English
• Published: SciPost 21-11-2024
• ISSN: 2542-4653; 2542-4653
• DOI: 10.21468/SciPostPhys.17.5.140

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.