1985/06/10 by N. V. Smith, N V Smith, S. D. Kevan +3 · 2 citations
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Molecular Junctions and Nanostructures #Semiconductor materials and interfaces
paper · doi:10.1088/0022-3719/18/16/013
crossref issued 1985/06/10 · crossref published 1985/06/10 · crossref published-print 1985/06/10 · openalex publication_date 1985/06/10 · crossref published-online 2000/11/23 · crossref created 2002/07/26 · crossref deposited 2020/04/11 · openalex created_date 2025/10/10 · crossref indexed 2026/07/27 · openalex updated_date 2026/07/30
Angle-resolved photoemission spectroscopy (ARPES) measurements of the E(k/sub ///) band structure are reported for 1T-TaS 2 and 2H-TaSe 2 at temperatures where commensurate CDWS are well developed. Empirical tight-binding calculations of the band structure in the presence of the experimentally known CDW superlattice are also reported. In the case of the square root 13* square root 13 CDW in 1T-TaS 2 , experiment and theory both reveal a gross distortion of the band structure, in which the Ta-derived d band collapses into three sub-band manifolds separated by gaps. The thirteenth electron is predicted to reside in a conduction band only 50 meV wide, where it is susceptible to a Mott-Anderson transition. In the case of 2H-TaSe 2 , additional peaks are seen in the ARPES data in the presence of the CDW, but the effects are too weak to distinguish between a band-structure distortion and weak Umklapp associated with the 3*3 superlattice. Calculated densities of states, decomposed according to the inequivalent atomic sites, are presented.