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

Abstract

The electronic structure of Na2Ti2Sb2O, a parent compound of the newly discovered titanium-based oxypnictide superconductors, 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 Na2Ti2Sb2O in the non-magnetic state, which indicating that there is no magnetic order in Na2Ti2Sb2O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na2Ti2Sb2O. Photon energy dependent ARPES results suggest that the electronic structure of Na2Ti2Sb2O 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 Na2Ti2Sb2O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime.

arXiv comment10 pages, 4 figures

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Cited by in corpus (6)

• Weak metal-metal transition in the vanadium oxytelluride Rb${}_{1-\delta }$V${}_2$Te${}_2$O
• Theoretical Prediction of the Nematic Orbital-Ordered State in Ti-Oxypnictide Superconductor BaTi2(As,Sb)2O
• Commensurate lattice distortion in the layered titanium oxypnictides Na${}_2$Ti${}_{2}P{n}_2$O ($Pn=$ As, Sb) determined by X-ray diffraction
• Exotic phase transition and superconductivity in layered titanium-oxypnictides implied by a computational phonon analysis
• Revealing the hidden order in BaTi2As2O via nuclear magnetic resonance
• Molecular orbital polarization in Na2Ti2Sb2O: microscopic route to metal-metal transition without spontaneous symmetry breaking