PUB - Publikationen an der Universität Bielefeld

The recently discovered superconductivity in MgB2 has created the world sensation. In spite of the relatively high superconducting transition temperature T-c = 39 K, the superconductivity is understood in terms of rare two gap superconductor with energy gaps attached to the sigma and pi-band. However, this simple model cannot describe the temperature dependent anisotropy in H-c2 or the temperature dependence of the anisotropic magnetic penetration depth. Here we propose a model with two anisotropic energy gaps with different shapes. Indeed the present model describes a number of peculiarities of MgB2 which have been revealed only recently through single crystal MgB2.