Phonon Dispersion and Electron-Phonon Coupling in MgB{sub 2} and AlB{sub 2}
We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB{sub 2} and the isostructural AlB{sub 2} within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. Complete phonon dispersion curves and Eliashberg functions {alpha}{sup 2}F are calculated for both systems. The main differences are related to high frequency in-plane boron vibrations, which are strongly softened in MgB{sub 2} and exhibit an exceptionally strong electron-phonon coupling. We also report on Raman measurements, which support the theoretical findings. Implications for the superconducting transition temperature are briefly discussed.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40204687
- Journal Information:
- Physical Review Letters, Vol. 86, Issue 25; Other Information: DOI: 10.1103/PhysRevLett.86.5771; Othernumber: PRLTAO000086000025005771000001; 019125PRL; PBD: 18 Jun 2001; ISSN 0031-9007
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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