Universal conductivity and the electrodynamics of graphite at high pressures
Abstract
We address the in-plane pressure-dependent electrodynamics of graphite through synchrotron based infrared spectroscopy and ab initio Density Functional Theory calculations. The Drude term remarkably increases upon pressure application, as a consequence of an enhancement of both electron and hole charge densities. This is due to the growth of the band dispersion along the k_z direction between the K and H points of the Brillouin zone. On the other hand, the mid-infrared optical conductivity between 800 and 5000 cm-1 is almost flat, and very weakly pressure dependent, at least up to 7 GPa. This demonstrates a surprising robustness of the graphene-like universal quantum conductance of graphite, even when the interlayer distance is significantly reduced.
Cite
@article{arxiv.1111.1126,
title = {Universal conductivity and the electrodynamics of graphite at high pressures},
author = {A. Perucchi and L. Baldassarre and C. Marini and P. Postorino and F. Bernardini and S. Massidda and S. Lupi},
journal= {arXiv preprint arXiv:1111.1126},
year = {2012}
}
Comments
5 pages, 4 figures; final version accepted in PRB