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Origin of Strong Coupling in Lithium under Pressure

Deepa Kasinathan·K. Koepernik·J. Kunes·H. Rosner·W. E. Pickett
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Abstract

In an attempt to provide a clearer understanding of the impressive increase in T_c under pressure in elemental Li, linear response calculation of the phonon dispersion curves, electron-phonon matrix elements, phonon linewidths and mode lambda's have been carried out on a finer mesh (24^3 in the Brillouin zone) than done previously, for the volume corresponding to 20 GPa pressure. The result illustrates the great need for a fine mesh (even finer than this) for converged results of lambda and the spectral function alpha^2 F. Although the initial pressure-induced transverse T_1 phonon instability (in harmonic approximation) near the symmetry point K has dominated attention, the current results show that the high value of T_c gets strong contributions from elsewhere in the zone, particularly from the longitudinal mode along (100).

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Deepa Kasinathan, K. Koepernik, J. Kunes, H. Rosner, W. E. Pickett. 2006-06-25. Origin of Strong Coupling in Lithium under Pressure. https://doi.org/10.1016/j.physc.2007.03.361

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