Electron correlation and fermi surface topology of NaxCoO2.
Electron correlation and fermi surface topology of NaxCoO2.
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DOI：
10.1103/physrevlett.94.206401
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发表时间：
2005-03
影响因子：
8.6
通讯作者：
Sen Zhou;Meng Gao;H. Ding;P. Lee;Ziqiang Wang
中科院分区：
文献类型：
--
作者：
Sen Zhou;Meng Gao;H. Ding;P. Lee;Ziqiang Wang
最近光电实验揭示的NaxCoO2的电子结构与能带理论预测有很大的偏差。由于相关的e'(g)带在钠掺杂浓度x的大范围内未能穿过费米能级，因此没有观察到局域密度近似计算预测的六个小费米表面口袋。此外，还观察到t（2g）配合物的显著带宽重整化。我们通过研究Hartree-Fock和强耦合Gutzwiller近似中的多轨道Hubbard模型表明，这些差异是由于强电子相关性引起的。在强局域库仑斥力作用下得到的准粒子色散和费米表面拓扑与实验结果吻合较好。
The electronic structure of NaxCoO2 revealed by recent photoemission experiments shows important deviations from band theory predictions. The six small Fermi surface pockets predicted by local-density approximation calculations have not been observed as the associated e'(g) band fails to cross the Fermi level for a wide range of sodium doping concentration x. In addition, significant bandwidth renormalizations of the t(2g) complex have been observed. We show that these discrepancies are due to strong electronic correlations by studying the multiorbital Hubbard model in the Hartree-Fock and strong-coupling Gutzwiller approximation. The quasiparticle dispersion and the Fermi surface topology obtained in the presence of strong local Coulomb repulsion are in good agreement with experiments.