Magneto-optical reflectivity of superconducting MgB2 single crystals

Abstract

We present magneto-optical reflectivity results in the basal-plane of the hexagonal $Mg{B}_2$. The data were collected on a mosaic of $Mg{B}_2$ single crystals with $T_c=38K$ from the ultraviolet down to the far infrared as a function of temperature and magnetic field oriented along the c-axis. In the far infrared there is a clear signature of the superconducting gap with a gap-ratio $2\Delta /k_B{T}_c\sim 1.2$, well below the weak-coupling value. The gap is suppressed in an external magnetic field, which is a function of temperature. We extract the upper critical field $H_{c2}$ along the c-axis. The temperature dependence of $H_{c2}$ is compatible with the Helfand-Werthamer behaviour.

arXiv comment6 pages (3 text-pages, 3 figures), submitted to PRL

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Cited by in corpus (11)

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• Multiband and impurity effects in infrared and optical spectra of MgB2
• Multi-Gap Superconductivity in MgB2: Magneto-Raman Spectroscopy
• Clean and Dirty Superconductivity in Pure, Al doped, and Neutron Irradiated MgB2: a Far-Infrared Study
• Two-band parallel conductivity at terahertz frequencies in the superconducting state of MgB${}_2$.
• Infrared properties of Mg${}_{1-x}$Al${}_x($B${}_{1-y}$C${}_y$)${}_2$ single crystals in the normal and superconducting state
• Looking at the superconducting gap of iron pnictides
• Revisiting optical properties of MgB${}_2$ with a high-quality sample prepared by a HPCVD method