Journal Article

FZJ-2019-06642

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Anisotropic spin fluctuations in detwinned FeSe

Chen, T. ; Chen, Y. ; Kreisel, A.Extern* ; Lu, X.Extern* ; Schneidewind, A.FZJ* ; Qiu, Y. ; Park, J. T.MLZ* ; Perring, T. G.Extern* ; Stewart, J. R.Extern* ; Cao, H. ; Zhang, R. ; Li, Y.Extern* ; Rong, Y. ; Wei, Y. ; Andersen, B. M.Extern* ; Hirschfeld, P. J. ; Broholm, C. ; Dai, P. (Corresponding author)Extern*

2019
Nature Publishing Group Basingstoke

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Please use a persistent id in citations: http://hdl.handle.net/2128/23692  doi:10.1038/s41563-019-0369-5

Abstract: Superconductivity in FeSe emerges from a nematic phase that breaks four-fold rotational symmetry in the iron plane. This phase may arise from orbital ordering, spin fluctuations or hidden magnetic quadrupolar order. Here we use inelastic neutron scattering on a mosaic of single crystals of FeSe, detwinned by mounting on a BaFe2As2 substrate to demonstrate that spin excitations are most intense at the antiferromagnetic wave vectors QAF = (±1, 0) at low energies E = 6–11 meV in the normal state. This two-fold (C2) anisotropy is reduced at lower energies, 3–5 meV, indicating a gapped four-fold (C4) mode. In the superconducting state, however, the strong nematic anisotropy is again reflected in the spin resonance (E = 3.6 meV) at QAF with incommensurate scattering around 5–6 meV. Our results highlight the extreme electronic anisotropy of the nematic phase of FeSe and are consistent with a highly anisotropic superconducting gap driven by spin fluctuations.

Keyword(s): Magnetic Materials (1st) ; Condensed Matter Physics (2nd) ; Magnetism (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)
2. 6212 - Quantum Condensed Matter: Magnetism, Superconductivity (POF3-621) (POF3-621)
3. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)

Experiment(s):

1. PANDA: Cold three axes spectrometer (SR2)
2. PUMA: Thermal three axes spectrometer (SR7)

Appears in the scientific report 2019

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Database coverage:
; ; BIOSIS Previews ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF >= 30 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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