Optical measurements of the superconducting gap in MgB2
arXiv:cond-mat/0103164 · doi:10.1007/s100510170191
Abstract
Far-infrared reflectivity studies on the polycrystalline intermetallic compound MgB_2 with a superconducting transition temperature T_c=39 K were performed at temperatures 20 K to 300 K. We observe a significant raise of the superconducting-to-normal state reflectivity ratio below 70 cm^{-1}, with a maximum at about 25-30 cm^{-1}, which gives a lower estimate of the superconducting gap of 2Î(0)\approx3-4 meV.
3 pages, 3 figures, revtex accepted by European Physics Journal B