Comment on “Exact solutions of the Lawrence-Doniach model for layered superconductors”

Abstract

In two recent publications [Phys. Rev. B 60, 7496 (1999); 63, 054508 (2001)] Kuplevakhsky has questioned the existence and stability of isolated Josephson vortices in layered superconductors. He argued that ``vortex planes'' rather than isolated vortices correspond to ``unconditional minimum'' of Gibbs free energy and ruled out ``any possibility of single Josephson vortex penetration.'' In this comment, I disprove those statements and demonstrate that isolated Josephson vortices penetrate layered superconductors and have considerably lower energy than vortex planes.