The optical response of the two-band superconductor MgB(2) has been studied in the 0.7-4 THz range on films with very low impurity level. The effect of the high-energy sigma gap is observed in the ratio R(S)/R(N) between the normal and superconducting state reflectance, while in a neutron irradiated film with a slightly higher impurity level, mainly the effect of the sigma gap is evident, as reported in previous experiments. At terahertz frequencies, the electrodynamics of MgB(2) can be well described by the two-band parallel conductivity model and is dominated by the pi bands when the impurity level is only slightly higher than that of an ultraclean sample.
Ortolani, M., Dore, P., DI CASTRO, D., Perucchi, A., Lupi, S., Ferrando, V., et al. (2008). Two-band parallel conductivity at terahertz frequencies in the superconducting state of MgB2. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 77 [10.1103/PhysRevB.77.100507].
Two-band parallel conductivity at terahertz frequencies in the superconducting state of MgB2
DI CASTRO, DANIELE;
2008-01-01
Abstract
The optical response of the two-band superconductor MgB(2) has been studied in the 0.7-4 THz range on films with very low impurity level. The effect of the high-energy sigma gap is observed in the ratio R(S)/R(N) between the normal and superconducting state reflectance, while in a neutron irradiated film with a slightly higher impurity level, mainly the effect of the sigma gap is evident, as reported in previous experiments. At terahertz frequencies, the electrodynamics of MgB(2) can be well described by the two-band parallel conductivity model and is dominated by the pi bands when the impurity level is only slightly higher than that of an ultraclean sample.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
