Electron-Phonon Coupling and the Soft Phonon Mode in TiSe$_2$

التفاصيل البيبلوغرافية
العنوان: Electron-Phonon Coupling and the Soft Phonon Mode in TiSe$_2$
المؤلفون: Weber, F., Rosenkranz, S., Castellan, J. -P., Osborn, R., Karapetrov, G., Hott, R., Heid, R., Bohnen, K. -P., Alatas, A.
المصدر: Phys. Rev. Lett. 107, 266401 (2011)
سنة النشر: 2011
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Strongly Correlated Electrons
الوصف: We report high-resolution inelastic x-ray measurements of the soft phonon mode in the charge-density-wave compound TiSe$_2$. We observe a complete softening of a transverse optic phonon at the L point, i.e. q = (0.5, 0, 0.5), at T ~ T_{CDW}. Renormalized phonon energies are observed over a large wavevector range $(0.3, 0, 0.5) \le \mathbf{q} \le (0.5, 0, 0.5)$. Detailed ab-initio calculations for the electronic and lattice dynamical properties of TiSe2 are in quantitative agreement with experimental frequencies for the phonon branch involving the soft mode. The observed broad range of renormalized phonon frequencies is directly related to a broad peak in the electronic susceptibility stabilizing the charge-density-wave ordered state. Our analysis demonstrates that a conventional electron-phonon coupling mechanism can explain a structural instability and the charge-density-wave order in TiSe_2 although other mechanisms might further boost the transition temperature.
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevLett.107.266401
URL الوصول: http://arxiv.org/abs/1105.3292
رقم الانضمام: edsarx.1105.3292
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevLett.107.266401