The metallic character of the GeBi2Te4 single crystals is probed using a combination of structural and physical properties measurements, together with density functional theory (DFT) calculations. The structural study shows distorted Ge coordination polyhedra, mainly of the Ge octahedra. This has a major impact on the band structure, resulting in bulk metallic behavior of GeBi2Te4, as indicated by DFT calculations. Such calculations place GeBi2Te4 in a class of a few known non-trivial topological metals, and explains why an observed Dirac point lies below the Fermi energy at about -0.12eV. A topological picture of GeBi2Te4 is confirmed by the observation of surface state modulations by scanning tunneling microscopy (STM).
@article{arxiv.1401.2407,
title = {Topological metal behavior in GeBi2Te4 single crystals},
author = {A. Marcinkova and J. K. Wang and C. Slavonic and Andriy H. Nevidomskyy and K. F. Kelly and Y. Filinchuk and E. Morosan},
journal= {arXiv preprint arXiv:1401.2407},
year = {2014}
}