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arXiv 0903.2218cond-mat.supr-con
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YBa2Cu4O8高温超导体中费米面异常非对称性的角分辨光电子能谱研究

Anomalous asymmetry of the Fermi surface in the YBa2Cu4O8 high temperature superconductor revealed by Angle Resolved Photoemission Spectroscopy

Takeshi Kondo, R. Khasanov, Y. Sassa, A. Bendounan, S. Pailhes, J. Chang, J. Mesot, H. Keller, N. D. Zhigadlo, M. Shi, S. M. Kazakov, J. Karpinski, A. Kaminski

摘要:

本文用微探针角分辨光电子能谱研究了高温超导体YBa_2Cu_4 O_8中CuO_2面的费米面和能带色散。我们发现一个强大的面内沿a和b轴方向之间的电子结构的不对称性。反键带的鞍点在a方向(pi,0)上的能量明显高于b方向(0,pi),而成键带则相反。我们表明,异常的带形是由于强烈的不对称性的双层带分裂,可能是由一个非平凡的杂交之间的飞机和链。这种不对称性对于解释Y-Ba-Cu-O(YBCO)族的关键性质,特别是超导能隙、输运和非弹性中子散射结果具有重要意义。

英文摘要:

We use microprobe Angle-Resolved Photoemission Spectroscopy to study the Fermi surface and band dispersion of the CuO2 planes in the high temperature superconductor, YBa2Cu4O8. We find a strong in-plane asymmetry of the electronic structure between directions along a and b axes. The saddle point of the antibonding band lies at a significantly higher energy in the a direction (pi,0) than the b direction (0,pi), whereas the bonding band displays the opposite behavior. We demonstrate that the abnormal band shape is due to a strong asymmetry of the bilayer band splitting, likely caused by a non-trivial hybridization between the planes and chains. This asymmetry has an important implication for interpreting key properties of the Y-Ba-Cu-O (YBCO) family, especially the superconducting gap, transport and results of inelastic neutron scattering.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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