Comment on "Case of thermodynamic failure in the Ginzburg-Landau approach to fluctuation superconductivity"

TL;DR

This paper discusses a theoretical critique of the Ginzburg-Landau approach, showing it predicts persistent voltages in superconducting loops, and compares these predictions with experimental observations, highlighting potential for experimental detection.

Contribution

It provides a theoretical analysis of thermodynamic failure in the Ginzburg-Landau theory concerning persistent voltages in superconducting loops, supported by experimental comparison.

Findings

Ginzburg-Landau theory predicts persistent voltages in nonuniform superconducting loops.

Experimental data supports the existence of these persistent voltages.

Connecting multiple rings in series increases the observable voltage.

Abstract

Jorge Berger shows theoretically in the paper Phys. Rev. B 109, 024501 (2024) that according to the Ginzburg-Landau theory the persistent current can create the persistent voltage, i.e. a dc voltage at thermodynamic equilibrium, on segments of nonuniform superconducting loop. A similar result was published early and was collaborated experimentally. The persistent power estimated by Berger is compared with the experimentally observed power. The attention of experimenters is drawn to the possibility to observe the persistent voltage thanks to its increase with the number of identical rings connected in series.