We investigate the conditions for the occurrence of the coexisting phases that exhibit singlet superconductivity and itinerant ferromagnetism arising from spin asymmetric bandwidths. The exact solution for a reduced BCS pairing model with spin dependent bandwidths is used to determine the ground-state diagram as a function of the coupling parameter, the total density, and the topology of the single-particle spectrum. A spin-polarized superconducting state is obtained in the regime of large pair couplings with a strong bandwidth asymmetry. The analysis reveals that, for such a type of ferromagnetism, small (large) values of the density of states at energies close to the edges of the band enhance (hinder) the tendency toward a coexistence of strong pairing correlations and finite spin polarizations.
Coexistence of strong pairing correlations and itinerant ferromagnetism arising from spin asymmetric bandwidths: A reduced BCS model study
Cuoco M;Noce C;
2008
Abstract
We investigate the conditions for the occurrence of the coexisting phases that exhibit singlet superconductivity and itinerant ferromagnetism arising from spin asymmetric bandwidths. The exact solution for a reduced BCS pairing model with spin dependent bandwidths is used to determine the ground-state diagram as a function of the coupling parameter, the total density, and the topology of the single-particle spectrum. A spin-polarized superconducting state is obtained in the regime of large pair couplings with a strong bandwidth asymmetry. The analysis reveals that, for such a type of ferromagnetism, small (large) values of the density of states at energies close to the edges of the band enhance (hinder) the tendency toward a coexistence of strong pairing correlations and finite spin polarizations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
