1209.5253 (Alaska Subedi et al.)

Electron-phonon superconductivity in $A$Pt$_3$P compounds: from weak to
strong coupling    [PDF]

Alaska Subedi, Luciano Ortenzi, Lilia Boeri

We study the newly-discovered Pt phosphides $A$Pt$_3$P ($A$=Sr, Ca, La) [T. Takayama, et al., Phys. Rev. Lett. 108, 237001] using first-principles calculations and Migdal-Eliashberg theory. Based on well-converged results, we exclude the charge-density wave scenario proposed by previous first-principles calculations. Instead, we find that all three compounds are well described by conventional s-wave superconductivity. The pairing increases from La to Ca and Sr due to changes in the electron-phonon matrix elements and low frequency phonons. Our picture is fully supported by comparison with the available experimental data. This allows us to rule out exotic and multiband contributions to the superconducting pairing.

View original: http://arxiv.org/abs/1209.5253