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arXiv · 1503.02333

In-plane Charge Fluctuations in Bismuth Sulfide Superconductors

Anushika Athauda·Junjie Yang·Seunghun Lee·Yoshikazu Mizuguchi·Keita Deguchi·Yoshihiko Takano·Osuke Miura·Despina Louca
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Abstract

Evidence for local charge fluctuations linked to a charge disproportionation of the Bi ions in the distorted lattice of superconducting LaO$_{1-x}$F$_{x}$ BiS$_{2}$ is presented. In-plane short-range distortions of sulfur atoms up to 0.3 Å in magnitude break site symmetry and create two distinct environments around Bi. Out-of-plane motion of apical sulfur brings it closer to the La-O/F doping layer with increasing $x$ that may lead to a charge transfer conduit between the doping layers and the superconducting BiS$_{2}$ planes. The mechanism for superconductivity may arise from the interplay between charge density fluctuations and an enhanced spin-orbit coupling suggested theoretically, that induces spin polarization.

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Anushika Athauda, Junjie Yang, Seunghun Lee, Yoshikazu Mizuguchi, Keita Deguchi, Yoshihiko Takano, Osuke Miura, Despina Louca. 2015-03-08. In-plane Charge Fluctuations in Bismuth Sulfide Superconductors. https://doi.org/10.1103/physrevb.91.144112

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