Home » Dmse » Highlight » Occam’s Razor Cuts Down Superconductor Classifications

Occam’s Razor Cuts Down Superconductor Classifications

Researchers have wrestled with the question of whether or not the newest superconducting materials fit within the traditional classifications. Superconductors can be divided into Type 1 and Type 2, depending on how they behave in a magnetic field.  However, magnesium diboride was discovered to have characteristics of both categories and has been dubbed “Type 1.5”.    Drawing on the fundamentals of Ginzburg-Landau theory, the basis of the two original types, a combination of theory and simulation has determined that a new class is not warranted. Close to the superconducting transition temperature (where the Ginzburg-Landau theory is valid), the energy of the interface between a normal and a superconducting region is described by the same universal function for Type 1 and Type 2 superconductors and also those that behave like both.  This makes the idea of Type 1.5 superconductivity unnecessary within the Ginzburg-Landau theory. The behavior of magnesium diboride can be understood in terms of Type 2 superconductivity. 

  1. J. Geyer, R. M. Fernandes, V. G. Kogan and J. Schmalian. Interface Energy of Two-Band Superconductors. Physical Review B, 2010, 82, 104521.  DOI: 10.1103/PhysRevB.82.104521. Editor’s Suggestion 
  2. V. G. Kogan and J. Schmalian. Ginzburg-Landau Theory of Two-Band Superconductors: Absence of Type-1.5 Superconductivity. Physical Review B, 2011, 83, 054515.  Editor’s Suggestion

(Back) - (Highlights Archive)