2004/01/19 by A. E. Koshelev, A. A. Golubov · 62 citations
Materials Science · Physics and Astronomy · #Anisotropy #Condensed matter physics #Critical current #Electronic band structure #Ginzburg–Landau theory #Iron-based superconductors research #Magnesium diboride #Physics #Quantum mechanics #Sigma #Superconductivity #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.92.107008
published in Physical Review Letters 92(10), 107008 (American Physical Society) · 4 pages, 2 fugures, Subm. Phys. Rev. Lett
arxiv created 2004/01/19 · openalex publication_date 2004/03/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is well established that the superconductivity in the recently discovered superconducting compound MgB2 resides in the quasi-two-dimensional band (sigma band) and three-dimensional band (pi band). We demonstrate that, due to such band structure, the anisotropic Ginzburg-Landau theory practically does not have a region of applicability, because gradient expansion in the c direction breaks down. In the case of a dirty pi band, we derive the simplest equations, which describe properties of such superconductors near Tc, and explore some consequences of these equations.