Photoemission study of the electronic structure and charge density waves of Na2Ti2Sb2O

• Published in: Scientific reports Vol. 5; no. 1; p. 9515
• Main Authors: Tan, S. Y., Jiang, J., Ye, Z. R., Niu, X. H., Song, Y., Zhang, C. L., Dai, P. C., Xie, B. P., Lai, X. C., Feng, D. L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.04.2015; Nature Publishing Group
• Subjects: 140/146; 639/766/119/1003; 639/766/119/544; Band structure; Energy; Humanities and Social Sciences; multidisciplinary; Polarization; Science; Spectroscopy; Temperature effects
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep09515

The electronic structure of Na 2 Ti 2 Sb 2 O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na 2 Ti 2 Sb 2 O in the non-magnetic state, which indicates that there is no magnetic order in Na 2 Ti 2 Sb 2 O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na 2 Ti 2 Sb 2 O. Photon energy dependent ARPES results suggest that the electronic structure of Na 2 Ti 2 Sb 2 O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV at 7 K, indicating that Na 2 Ti 2 Sb 2 O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime.