title: Electronic structures of RTe2 (R = La,Ce): a clue to the pressure-induced superconductivity in CeTe1.82.
abstract: Electronic structures of RTe2 (R=La,Ce) have been investigated by using the local spin density approximation (LSDA) and the LSDA + U (U: on-site Coulomb interaction) band methods. Both LaTe2 and CeTe2 show the very similar Fermi surface nesting features along the [100] direction, which drive the charge-density wave (CDW) instability in the Te(1) sheets. The contribution near E(F) from Ce 4f states is negligible in agreement with the measured ARPES spectra. In the semimetallic CDW-distorted RTe2, both Te vacancy and pressure induce the charge transfer from Te(1) 5p to R 5d states, producing the enhanced density of states at E(F). We suggest that these increased self-doped Te(1) 5p hole carriers are responsible for the pressure-induced superconductivity in nonstoichiometric CeTe1.82.
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Shim
authors.forename: J-S
authors.initials: JS
authors.lastname: Kang
authors.forename: B I
authors.initials: BI
authors.lastname: Min