Abstract
Motivated by the recent discovery of superconductivity in Ca- and Yb-intercalated graphite ( and ) and from the ongoing debate on the nature and role of the interlayer state in this class of compounds, in this work we critically study the electron-phonon properties of a simple model based on primitive graphite. We show that this model captures an essential feature of the electron-phonon properties of the graphite intercalation compounds, namely, the existence of a strong dormant electron-phonon interaction between interlayer and electrons, for which we provide a simple geometrical explanation in terms of Wannier-like functions. Our findings correct the oversimplified view that nearly free-electron states cannot interact with the surrounding lattice and explain the empirical correlation between the filling of the interlayer band and the occurrence of superconductivity in graphite intercalation compounds.
6 More- Received 15 January 2007
DOI:https://doi.org/10.1103/PhysRevB.76.064510
©2007 American Physical Society