Proximity to Fermi-surface topological change in superconducting LaO0.54F0.46BiS2

K. Terashima; J. Sonoyama; T. Wakita; M. Sunagawa; K. Ono; H. Kumigashira; T. Muro; M. Nagao; S. Watauchi; I. Tanaka; H. Okazaki; Y. Takano; O. Miura; Y. Mizuguchi; H. Usui; K. Suzuki; K. Kuroki; Y. Muraoka; T. Yokoya

doi:10.1103/physrevb.90.220512

arXiv · 1412.7786

Proximity to Fermi-surface topological change in superconducting LaO0.54F0.46BiS2

K. Terashima·J. Sonoyama·T. Wakita·M. Sunagawa·K. Ono·H. Kumigashira·T. Muro·M. Nagao·S. Watauchi·I. Tanaka·H. Okazaki·Y. Takano·O. Miura·Y. Mizuguchi·H. Usui·K. Suzuki·K. Kuroki·Y. Muraoka·T. Yokoya

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Abstract

The electronic structure of nearly optimally-doped novel superconductor LaO$_{1-x}$F$_x$BiS$_2$ (${\it x}$ = 0.46) was investigated using angle-resolved photoemission spectroscopy (ARPES). We clearly observed band dispersions from 2 to 6 eV binding energy and near the Fermi level (${\it E}_{\rm F}$), which are well reproduced by first principles calculations when the spin-orbit coupling is taken into account. The ARPES intensity map near ${\it E}_{\rm F}$ shows a square-like distribution around the $\Gamma$(Z) point in addition to electronlike Fermi surface (FS) sheets around the X(R) point, indicating that FS of LaO$_{0.54}$F$_{0.46}$BiS$_2$ is in close proximity to the theoretically-predicted topological change.

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K. Terashima, J. Sonoyama, T. Wakita, M. Sunagawa, K. Ono, H. Kumigashira, T. Muro, M. Nagao, S. Watauchi, I. Tanaka, H. Okazaki, Y. Takano, O. Miura, Y. Mizuguchi, H. Usui, K. Suzuki, K. Kuroki, Y. Muraoka, T. Yokoya. 2014-12-25. Proximity to Fermi-surface topological change in superconducting LaO0.54F0.46BiS2. https://doi.org/10.1103/physrevb.90.220512

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