Title: Electronic structure of pyrochlore Cd(2)Re(2)O(7)
Authors: Huang, Shih-Wen
Jeng, Horng-Tay
Lin, J-Y
Chang, W. J.
Chen, J. M.
Lee, G. H.
Berger, H.
Yang, H. D.
Liang, Keng S.
Department of Electrophysics
Institute of Physics
Issue Date: 13-May-2009
Abstract: Detailed band structure calculations have been performed for Cd(2)Re(2)O(7) in high-, middle- and low-temperature (T) phases. The calculations are based on the observed lattice structures from x-ray diffraction measurements. The spin-orbit interaction is incorporated self-consistently in both the generalized gradient approximation (GGA) and the GGA plus Hubbard U (GGA + U) approaches. It is found that the on-site U has negligible effects on the Re 5d band structures; therefore both the GGA and GGA + U Re 5d band energies agree well with the observed O K-edge x-ray absorption spectroscopy (XAS) spectrum, whereas the Cd 4d band energy observed from photoemission spectroscopy can only be correctly reproduced by GGA + U calculations, indicating the relatively itinerant Re 5d and localized Cd 4d electrons. On the other hand, the spin-orbit coupling gives rise to nontrivial spin and orbital magnetic moments for the middle-T phase. Most unexpectedly, we found that the low-T phase exhibits quasi-two-dimensional Fermi surfaces. The calculated carrier numbers for the three phases are, at least qualitatively, consistent with the measured Hall coefficient.
URI: http://dx.doi.org/10.1088/0953-8984/21/19/195602
ISSN: 0953-8984
DOI: 10.1088/0953-8984/21/19/195602
Volume: 21
Issue: 19
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