2002/04/30 by A. I. Posazhennikova, A. I Posazhennikova, T. Dahm +3 · 1 citation
Materials Science · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #cond-mat.supr-con
paper · pdf · doi:10.1209/epl/i2002-00330-9
published as Europhys. Lett. 60, 134 (2002) · 7 pages, 6 figures, some minor changes, to appear in Europhys. Lett
arxiv created 2002/07/23 · openalex publication_date 2002/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The recently discovered superconductivity in MgB 2 has captured world attention due to its simple crystal structure and relatively high superconducting transition temperature T c = 39 K. It appears to be generally accepted that it is phonon-mediated s -wave BCS-like superconductivity. Surprisingly, the strongly temperature-dependent anisotropy of the upper critical field, observed experimentally in magnesium diboride single crystals, is still lacking a consistent theoretical explanation. We propose a simple single-gap anisotropic s -wave order parameter in order to compare its implications with the predictions of a multi-gap isotropic s -wave model. The quasiparticle density of states, thermodynamic properties, NMR spin-lattice relaxation rate, optical conductivity, and H c2 anisotropy have been analyzed within this anisotropic s -wave model. We show that the present model can capture many aspects of the unusual superconducting properties of the MgB 2 compound, though more experimental data appear to be necessary from single-crystal MgB 2 .