2013/11/20 by T Qian, T. Qian, H. Miao +34
Chemistry · Materials Science · Physics and Astronomy · #2D Materials and Applications #Density of states #Electronic structure #Fermi level #Inorganic Chemistry and Materials #Phase (matter) #Phase transition #Phase-change materials and chalcogenides #Saddle #Saddle point #Singularity #Superstructure #Van Hove singularity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1088/1367-2630/16/12/123038
published as New Journal of Physics 16 (2014) 123038 · 5 pages, 4 fitures
arxiv created 2013/11/20 · openalex publication_date 2014/12/15 · arxiv updated 2014/12/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have investigated the electronic states of IrTe 2 by using angle-resolved photoemission spectroscopy to elucidate the origin of the structural phase transition. Both the Ir 4f and Te 4d core level spectra exhibit dramatic splitting below the phase transition temperature T s , suggesting that there exist two inequivalent Ir and Te sites with distinctly different electronic states in the distorted phase. The band related to the saddle points at the Fermi level ( E F ) is strongly reconstructed, which removes the van Hove singularity from E F below T s . The wavevector connecting the adjacent saddle points is consistent with the in-plane superstructure modulation wavevector. These results indicate that the phase transition in IrTe 2 is intimately associated with the saddle points. As the van Hove singularity mainly originates from the Te p x + p y orbitals, the Te 5p electronic states play a dominant role in the structural phase transition.