Publication Date:
2016-10-12
Description:
Author(s): N. R. Davies, M. C. Rahn, H. C. Walker, R. A. Ewings, D. N. Woodruff, S. J. Clarke, and A. T. Boothroyd Layered molecular-intercalated iron selenides (FeSe) show great promise as a class of high- T c unconventional superconductors, with a T c as high as 45 K reported so far. The FeSe layers in these materials also show structural and electronic similarities to monolayer FeSe on SrTiO 3 , where T c values up to 65 K have been observed. Information on the superconducting properties of these materials may provide vital insight into the unconventional mechanism of high-temperature superconductivity in iron-based compounds. One property of particular interest is the symmetry of the superconducting gap function on the Fermi surface, which is a key prediction for any theory of superconductivity. However, a precise experimental determination of this has proven elusive in the iron-based superconductors. In this paper, the authors study the LiOD-intercalated FeSe derivative Li 1 − x Fe x ODFe 1 − y Se via inelastic neutron scattering, detecting a spin resonance which appears in the superconducting state below the pair breaking energy 2 Δ . This shows that superconductivity in this compound is unconventional and, in conjunction with previous ARPES and STS results, strongly constrains the possible superconducting gap symmetries in this material. [Phys. Rev. B 94, 144503] Published Mon Oct 10, 2016
Keywords:
Superfluidity and superconductivity
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
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