On the thermodynamics of a superconducting ring interrupted by a weak superconducting junction

✍ Scribed by R. de Bruyn Ouboter

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 884 KB
• Volume: 154
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(88)90016-6

✦ Synopsis

A superconducting ring interrupted by a weak Josephson junction can have two metastable magnetic flux states separated by a potential energy barrier in case an external magnetic field of appropriate strength is applied. The thermodynamic Gibbs surface of this system is constructed: i.e. the relevant part of the magnetic Gibbs potential as a function of the applied magnetic flux and the temperature is shown. The relevant contribution to the entropy and the self-induced circulating current are the corresponding partial derivatives of the Gibbs function. From the Gibbs function and the entropy the magnetic enthalpy is found.

The calculations presented here are of relevance in interpreting thermodynamic fluctuation phenomena in the total embraced magnetic flux which are determined by the magnetic availability of the system with respect to the surroundings fixed by the temperature of the heat reservoir and the external magnetic field.