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arXiv · 1604.04364

Angle-resolved spectroscopy study of Ni-based superconductor SrNi$_2$As$_2$

L. -K. Zeng·P. Richard·A. van Roekeghem·J. -X. Yin·S. -F. Wu·Z. G. Chen·N. L. Wang·S. Biermann·T. Qian·H. Ding
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Abstract

We performed an angle-resolved photoemission spectroscopy study of the Ni-based superconductor SrNi$_2$As$_2$. Electron and hole Fermi surface pockets are observed, but their different shapes and sizes lead to very poor nesting conditions. The experimental electronic band structure of SrNi$_2$As$_2$ is in good agreement with first-principles calculations after a slight renormalization (by a factor 1.1), confirming the picture of Hund's exchange-dominated electronic correlations decreasing with increasing filling of the $3d$ shell in the Fe-, Co- and Ni-based compounds. These findings emphasize the importance of Hund's coupling and $3d$-orbital filling as key tuning parameters of electronic correlations in transition metal pnictides.

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L. -K. Zeng, P. Richard, A. van Roekeghem, J. -X. Yin, S. -F. Wu, Z. G. Chen, N. L. Wang, S. Biermann, T. Qian, H. Ding. 2016-04-15. Angle-resolved spectroscopy study of Ni-based superconductor SrNi$_2$As$_2$. https://doi.org/10.1103/physrevb.94.024524

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