Suppression of Superconductivity by Twin Boundaries in FeSe

Can-Li Song, Yi-Lin Wang, Ye-Ping Jiang, Lili Wang, Ke He, Xi Chen, Jennifer E. Hoffman, Xu-Cun Ma, and Qi-Kun Xue
Phys. Rev. Lett. 109, 137004 – Published 27 September 2012
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Low-temperature scanning tunneling microscopy and spectroscopy are employed to investigate twin boundaries in stoichiometric FeSe films grown by molecular beam epitaxy. Twin boundaries can be unambiguously identified by imaging the 90° change in the orientation of local electronic dimers from Fe site impurities on either side. Twin boundaries run at approximately 45° to the Fe-Fe bond directions, and noticeably suppress the superconducting gap, in contrast with the recent experimental and theoretical findings in other iron pnictides. Furthermore, vortices appear to accumulate on twin boundaries, consistent with the degraded superconductivity there. The variation in superconductivity is likely caused by the increased Se height in the vicinity of twin boundaries, providing the first local evidence for the importance of this height to the mechanism of superconductivity.

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  • Received 12 March 2012


© 2012 American Physical Society

Authors & Affiliations

Can-Li Song1,2,3, Yi-Lin Wang1, Ye-Ping Jiang1,2, Lili Wang1, Ke He1, Xi Chen2, Jennifer E. Hoffman3, Xu-Cun Ma1,*, and Qi-Kun Xue1,2,†

  • 1State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 2State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
  • 3Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA

  • *

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Vol. 109, Iss. 13 — 28 September 2012

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Heating up of Superconductors
January 27, 2017

This collection marks the 30th anniversary of the discovery of high-temperature superconductors. The papers selected highlight some of the advances that have been made to date, both in understanding why these compounds behave in the way they do, and in utilizing them in applications. The papers included in the collection have been made free to read.

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