Superconducting properties of MgB2 from first principles

The discovery of superconductivity in MgB2, with a rather high transition temperature, has triggered a large number of theoretical and experimental investigations on important issues such as, e.g., the role of gap anisotropy over the Fermi surface (multi-gap superconductivity). We report here the re...

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Bibliographic Details
Main Author: Floris, A. (author)
Other Authors: Sanna, A. (author), Lüders, M. (author), Profeta, G. (author), Lathiotakis, N. N. (author), Marques, M. A. L. (author), Franchini, C. (author), Gross, E. K. U. (author), Continenza, A. (author), Massidda, S. (author)
Format: article
Language:eng
Published: 2007
Subjects:
Online Access:http://hdl.handle.net/10316/4376
Country:Portugal
Oai:oai:estudogeral.sib.uc.pt:10316/4376
Description
Summary:The discovery of superconductivity in MgB2, with a rather high transition temperature, has triggered a large number of theoretical and experimental investigations on important issues such as, e.g., the role of gap anisotropy over the Fermi surface (multi-gap superconductivity). We report here the results obtained in this compound using the density functional theory for superconductors, recently proposed by the authors. Without invoking any adjustable parameters, such as [mu]*, we obtain the transition temperature, the gaps, and the specific heat in very good agreement with experiment. Moreover, our calculations allow for a detailed study of how the phonon-mediated attraction and Coulomb repulsion act differently on [sigma] and [pi] states, thereby stabilizing the observed superconducting phase.