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arXiv · 1402.1833

Observation of anomalous temperature dependence of spectrum on small Fermi surfaces in a BiS2-based superconductor

L. K. Zeng·X. B. Wang·J. Ma·P. Richard·S. M. Nie·H. M. Weng·N. L. Wang·Z. Wang·T. Qian·H. Ding
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Abstract

We performed an angle-resolved photoemission spectroscopy study of the BiS2-based superconductor Nd(O,F)BiS2. Two small electron-like Fermi surfaces around X (pi, 0) are observed, which enclose 2.4% and 1.1% of the Brillouin zone area, respectively, corresponding to an electron doping of 7% per Bi site. The low-energy spectrum consists of a weakly-dispersing broad hump and a dispersive branch, which follows well the calculated band dispersion. This hump is drastically suppressed with increasing temperature, while the dispersive branch is essentially unaffected. The anomalous thermal effect indicates a highly interacting electronic state, in which the superconducting pairing develops.

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L. K. Zeng, X. B. Wang, J. Ma, P. Richard, S. M. Nie, H. M. Weng, N. L. Wang, Z. Wang, T. Qian, H. Ding. 2014-02-08. Observation of anomalous temperature dependence of spectrum on small Fermi surfaces in a BiS2-based superconductor. https://doi.org/10.1103/physrevb.90.054512

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