English

Topology and Phase Transitions in the Little-Parks Experiment

supr-con 2008-02-03 v1 Superconductivity Quantum Physics

Abstract

This is an analytic study of the problem of transitions between normal and superconducting phases for a sample which encloses a magnetic flux. A preliminary study of this problem, based on numerical minimization of the free energy for a particular form of the thickness of the sample, was published in Phys. Rev. Lett. {\bf 75}, 320 (1995). For a sample of uniform thickness the order parameter is uniform, but even infinitesimal deviations from uniform thickness give rise to a singly connected state in which the order parameter vanishes at a suitable layer, so that the superconducting part does not enclose the magnetic field. The stability domain of this singly connected state is a line segment in the magnetic field-temperature plane, delimited by two critical points. The phase diagram contains several bifurcation lines, which are systematically analyzed.

Keywords

Cite

@article{arxiv.supr-con/9608001,
  title  = {Topology and Phase Transitions in the Little-Parks Experiment},
  author = {Jorge Berger and Jacob Rubinstein},
  journal= {arXiv preprint arXiv:supr-con/9608001},
  year   = {2008}
}

Comments

Latex, 26 pages, 5 figs upon request