Unconventional phonon-mediated superconductivity in MgB2

2001/11/14 by Guo-meng Zhao, G. M. Zhao
Materials Science · Physics and Astronomy · #Band gap #Energy (signal processing) #Exponent #Iron-based superconductors research #Mass gap #Physics of Superconductivity and Magnetism #Specific heat #Superconductivity #Superconductivity in MgB2 and Alloys #cond-mat.supr-con

paper · pdf · doi:10.1088/1367-2630/4/1/303

4 pages, 1 figures

arxiv created 2001/11/14 · openalex publication_date 2002/02/12 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We have evaluated the total carrier mass enhancement factor f_t for MgB₂ from two independent experiments (specific heat and upper critical field). These experiments consistently show that f_t = 3.1±0.1. The unusually large f_t is incompatible with the measured reduced gap (2Δ (0)/k_BT_c = 4.1) and the total isotope-effect exponent (α = 0.28±0.04) within the conventional phonon-mediated model. We propose an unconventional phonon-mediated mechanism, which is able to quantitatively explain the values of T_c, f_t, α, and the reduced energy gap in a consistent way.

Citations

• The complex nature of superconductivity in MgB2 as revealed by the reduced total isotope effect
• Current-voltage characteristics of the two-dimensionalXYmodel with Monte Carlo dynamics
• Nonadiabatic polaronic superconductivity in MgB2 and cuprates
• Properties of boson-exchange superconductors
• Strong electron-phonon coupling in superconductingMgB2: A specific heat study
• Phonon Dispersion and Electron-Phonon Coupling inMgB2andAlB2
• Phonon Density of States inMgB2