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arXiv · 1602.04949

Orbital selectivity of layer resolved tunneling on iron superconductor Ba0.6K0.4Fe2As2

J. -X. Yin·X. -X. Wu·Jian Li·Zheng Wu·J. -H. Wang·C. -S. Ting·P. -H. Hor·X. J. Liang·C. L. Zhang·P. C. Dai·X. C. Wang·C. Q. Jin·G. F. Chen·J. P. Hu·Z. -Q. Wang·Ang Li·H. Ding·S. H. Pan
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Abstract

We use scanning tunneling microscopy/spectroscopy (STM/S) to elucidate the Cooper pairing of the iron pnictide superconductor Ba0.6K0.4Fe2As2. By a cold-cleaving technique, we obtain atomically resolved termination surfaces with different layer identities. Remarkably, we observe that the low-energy tunneling spectrum related to superconductivity has an unprecedented dependence on the layer-identity. By cross-referencing with the angle-revolved photoemission results and the tunneling data of LiFeAs, we find that tunneling on each termination surface probes superconductivity through selecting distinct Fe-3d orbitals. These findings imply the real-space orbital features of the Cooper pairing in the iron pnictide superconductors, and propose a new and general concept that, for complex multi-orbital material, tunneling on different terminating layers can feature orbital selectivity.

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J. -X. Yin, X. -X. Wu, Jian Li, Zheng Wu, J. -H. Wang, C. -S. Ting, P. -H. Hor, X. J. Liang, C. L. Zhang, P. C. Dai, X. C. Wang, C. Q. Jin, G. F. Chen, J. P. Hu, Z. -Q. Wang, Ang Li, H. Ding, S. H. Pan. 2016-02-16. Orbital selectivity of layer resolved tunneling on iron superconductor Ba0.6K0.4Fe2As2. https://doi.org/10.1103/physrevb.102.054515

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