Two-band parallel conductivity at terahertz frequencies in the superconducting state of MgB${}_2$.

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 $\pi$-gap is evident as reported in previous experiments. At terahertz frequencies, the electrodynamic 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 ultra-clean sample.

4 pages, 3 figures

References in corpus (4)

• Point-contact spectroscopy in neutron-irradiated Mg^{11}B_2
• Multiband and impurity effects in infrared and optical spectra of MgB2
• Infrared properties of Mg${}_{1-x}$Al${}_x($B${}_{1-y}$C${}_y$)${}_2$ single crystals in the normal and superconducting state
• Probing the electron-phonon coupling in MgB2 through magnetoresistance measurements in neutron irradiated thin films

Cited by in corpus (6)

• Nonlinear optical response of collective modes in multiband superconductors assisted by nonmagnetic impurities
• Multi-gap superconductivity in a BaFe1.84Co0.16As2 film from optical measurements at terahertz frequencies
• High-order nonlinear terahertz probing of the two-band superconductor MgB${}_2$: Third- and fifth-order harmonic generation
• Multi-Dimensional Coherent Spectroscopy of Light-Driven States and their Collective Modes in Multi-Band Superconductors
• Two-band conductivity of a FeSe${}_{0.5}$Te${}_{0.5}$ film by reflectance measurements in the terahertz and infrared range
• Electrodynamics of superconducting pnictide superlattices