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arXiv · 1112.2259

Orbital characters of three-dimensional Fermi surfaces in Eu2-xSrxNiO4 as probed by soft-x-ray angle-resolved photoemission spectroscopy

M. Uchida·K. Ishizaka·P. Hansmann·X. Yang·M. Sakano·J. Miyawaki·R. Arita·Y. Kaneko·Y. Takata·M. Oura·A. Toschi·K. Held·A. Chainani·O. K. Andersen·S. Shin·Y. Tokura
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Abstract

The three-dimensional Fermi surface structure of hole-doped metallic layered nickelate Eu2-xSrxNiO4 (x=1.1), an important counterpart to the isostructural superconducting cuprate La2-xSrxCuO4, is investigated by energy-dependent soft-x-ray angle-resolved photoemission spectroscopy. In addition to a large cylindrical hole Fermi surface analogous to the cuprates, we observe a Gamma-centered 3z2-r2-derived small electron pocket. This finding demonstrates that in the layered nickelate the 3z2-r2 band resides close to the x2-y2 one in energy. The resultant multi-band feature with varying orbital character as revealed may strongly work against the emergence of the high-temperature superconductivity.

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M. Uchida, K. Ishizaka, P. Hansmann, X. Yang, M. Sakano, J. Miyawaki, R. Arita, Y. Kaneko, Y. Takata, M. Oura, A. Toschi, K. Held, A. Chainani, O. K. Andersen, S. Shin, Y. Tokura. 2011-12-10. Orbital characters of three-dimensional Fermi surfaces in Eu2-xSrxNiO4 as probed by soft-x-ray angle-resolved photoemission spectroscopy. https://doi.org/10.1103/physrevb.84.241109

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