Manzoni, G.Gragnaniello, L.Autes, G.Kuhn, T.Sterzi, A.Cilento, F.Zacchigna, M.Enenkel, V.Vobornik, I.Barba, L.Bisti, F.Bugnon, Ph.Magrez, A.Strocov, V. N.Berger, H.Yazyev, O. V.Fonin, M.Parmigiani, F.Crepaldi, A.2017-02-172017-02-172017-02-17201610.1103/PhysRevLett.117.237601https://infoscience.epfl.ch/handle/20.500.14299/134617WOS:000391391400018The complex electronic properties of ZrTe5 have recently stimulated in-depth investigations that assigned this material to either a topological insulator or a 3D Dirac semimetal phase. Here we report a comprehensive experimental and theoretical study of both electronic and structural properties of ZrTe5, revealing that the bulk material is a strong topological insulator (STI). By means of angle-resolved photoelectron spectroscopy, we identify at the top of the valence band both a surface and a bulk state. The dispersion of these bands is well captured by ab initio calculations for the STI case, for the specific interlayer distance measured in our x-ray diffraction study. Furthermore, these findings are supported by scanning tunneling spectroscopy revealing the metallic character of the sample surface, thus confirming the strong topological nature of ZrTe5.text::journal::journal article::research article