Electron-momentum dependence of electron-phonon coupling underlies dramatic phonon renormalization in YNi2B2C

Abstract

Phonon anomalies are commonly attributed to Fermi-surface nesting or phonon anharmonicity, but these mechanisms do not apply in all cases. Here, the authors propose a new mechanism based on electron-momentum-dependent electron-phonon coupling in the case of YNi2B2C, that could also apply to other materials.