Reply to Comment on ‘Reversible superconducting-normal phase transition in a magnetic field: the energy-momentum balance including the velocity field of the Berry connection from many-body wave functions’

Abstract

Abstract Nikulov commented that the latent heat is not included in our paper (2024 Physica Scripta 99 015952); it is included although we did not use it. His comment is based on the Helmholtz free energy with controlling variables T and B (T is the temperature of the sample and B is the magnitude of the magnetic field B); however, the relevant energy is the Gibbs free energy in the experimental situation where controlling variables are T and H (H is the magnitude of the applied magnetic field H); and our paper is based on it. His idea of the latent heat is not correct; it arises from the discontinuity of the derivative on the free energy with respect to temperature at the phase transition point, and related to the difference of entropies in the superconducting and normal phases; our theory includes it, although we did not use it. The Joule heating problem is actually the lack of the mechanism in the standard theory that enables reversible disappearance of the supercurrent during the superconducting to normal phase transition in a magnetic field. A new theory put forward by us has it; besides, it preserves the major results of the BCS theory. It may be a theory encompasses the BCS one.