First-order phase transition by a spin-flip potential in BCS superconductivity
Abstract
A spin-flip potential V is added to a BCS Hamiltonian in order to study its effect on the superconducting phase from a statistical physics point of view. The spin-flip potential could also be understood as a simplified way of representing the effect of impurities in a conventional superconductor. We found that the competition between the pairing and the spin-flip effect gives rise to a first-order phase transition for a range of values of V, before the total destruction of the superconducting order. The phase diagram shows a tricritical point in a frontier line which is topologically similar to those found in the phase diagrams of some Ising-like models as the Blume-Capel model. The first-order frontier was obtained numerically by free energy minimization.
- Publication:
-
Physica C Superconductivity
- Pub Date:
- September 2019
- DOI:
- 10.1016/j.physc.2019.05.007
- arXiv:
- arXiv:1801.07377
- Bibcode:
- 2019PhyC..564...75R
- Keywords:
-
- Condensed Matter - Statistical Mechanics
- E-Print:
- doi:10.1016/j.physc.2019.05.007