Phonon Dispersion and Lifetimes in MgB2

作者：Abhay Shukla, Matteo Calandra, M. d’Astuto, Michele Lazzeri, Francesco Mauri, Christophe Bellin, Michael H. Krisch, J. Karpiński, Sergey M. Kazakov, J. Jun, Dario Daghero, Krzysztof Parliński · 发表于：Physical Review Letters · 年份：2003 · DOI：10.1103/physrevlett.90.095506 · 被引用次数：161 · 研究领域：Superconductivity in MgB2 and Alloys、Thermal Expansion and Ionic Conductivity、Physics of Superconductivity and Magnetism

We measure phonon dispersion and linewidth in a single crystal of ${\mathrm{M}\mathrm{g}\mathrm{B}}_{2}$ along the $\ensuremath{\Gamma}\mathrm{\text{\ensuremath{-}}}A$, $\ensuremath{\Gamma}\mathrm{\text{\ensuremath{-}}}M$, and $A\mathrm{\text{\ensuremath{-}}}L$ directions using inelastic x-ray scattering. We use density functional theory to compute the effect of both electron-phonon coupling and anharmonicity on the linewidth, obtaining excellent agreement with experiment. Anomalous broadening of the ${E}_{2g}$ phonon mode is found all along $\ensuremath{\Gamma}\mathrm{\text{\ensuremath{-}}}A$. The dominant contribution to the linewidth is always the electron-phonon coupling.