Electronic structures of RTe2-δ (R =Ce, La)

Electronic structures of RTe_2-δ (R =Ce, La)

Ji Hoon Shim¹, S. J. Youn², and B. I. Min¹

¹Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea

²Department of Physics Education, Gyeongsang National University, Jinju 660-701, Korea

We have investigated the electronic structures of RTe_2-δ (R =Ce, La) using the LSDA and the LSDA+U 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. 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. Total energy calculation indicates that CeTe₂ has the ABBA-type antiferromagnetic configuration but the stability is not so strong. Based on our finding, we have discussed the origin of the pressure-induced superconductivity in CeTe_1.82.