Estudo da Criticalidade em supercondutores sob ação da interação spin-flip

Abstract

The phenomenon caused by the spin-flip V interaction introduced in a superconducting Hamiltonian type BCS, aims to study a possible thermodynamic effect caused by the addition of a magnetic impurity in a superconductor. The spin-flip potential can also be understood as a simplified way to represent the effect of impurities in a conventional superconductor. We found that the competition between the paired electrons and the spin-flip effect generates a first order phase transition for given values of V that is, for potential critics, before the superconducting phase is completely destroyed. The phase diagram shows a trichritic point on a boundary line that agrees with hybridization results in superconductors where the second-order to first-order transition line occurs when the pair break is due to thermal fluctuations. In order to obtain the first order frontier points, we counted on the aid of computational numerical calculations to minimize the free energy of the system and verified the extent to which the magnetic impurities present influenced the critical temperature of the superconductor.