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arXiv · 0912.5089

Observation of intertwined Fermi surface topology, orbital parity symmetries and electronic interactions in iron arsenide superconductors

L. A. Wray·D. Hsieh·Y. Xia·S. -Y. Xu·D. Qian·G. F. Chen·J. L. Luo·N. L. Wang·M. Z. Hasan
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Abstract

We present a polarization and topology resolved study of the low energy band structure in optimally doped superconducting Ba0.6K0.4Fe2As2 using angle resolved photoemission spectroscopy. Polarization-contrasted measurements allow us to identify and trace all low energy bands expected in models, revealing unexpected symmetry breaking and a surprisingly intertwined Fermi surface topology of hole-like bands near the Brillouin zone center. Band structure correlations across the Gamma-M spin fluctuation wavevector are compared with the superconducting gap anisotropy which suggest a partial scenario for spin-mediated interband instability contributing to superconductivity in the hole doped regime.

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L. A. Wray, D. Hsieh, Y. Xia, S. -Y. Xu, D. Qian, G. F. Chen, J. L. Luo, N. L. Wang, M. Z. Hasan. 2009-12-27. Observation of intertwined Fermi surface topology, orbital parity symmetries and electronic interactions in iron arsenide superconductors. https://arxiv.org/abs/0912.5089

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