Polarized neutron scattering studies of magnetic excitations in iron-selenide superconductor Li0.8Fe0.2ODFeSe (Tc= 41 K)

Die Hu; Yu Feng; Jitae T Park; Hongliang Wo; Qisi Wang; Frédéric Bourdarot; Alexandre Ivanov; Jun Zhao

doi:10.1088/1361-648X/ac1d16

Polarized neutron scattering studies of magnetic excitations in iron-selenide superconductor Li_0.8Fe_0.2ODFeSe (T_c= 41 K)

J Phys Condens Matter. 2021 Sep 1;33(45). doi: 10.1088/1361-648X/ac1d16.

Authors

Die Hu¹, Yu Feng¹, Jitae T Park², Hongliang Wo¹, Qisi Wang¹, Frédéric Bourdarot³, Alexandre Ivanov⁴, Jun Zhao^{1

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Affiliations

¹ State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China.
² Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, D-85748 Garching, Germany.
³ Université Grenoble Alpes, CEA, INAC, MEM MDN, F-38000 Grenoble, France.
⁴ Institute Laue-Langevin, 71 Avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France.
⁵ Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, People's Republic of China.
⁶ Shanghai Qi Zhi Institute, Shanghai, 200232, People's Republic of China.
⁷ Shanghai Research Center for Quantum Sciences, Shanghai 201315, People's Republic of China.

PMID: 34384050
DOI: 10.1088/1361-648X/ac1d16

Abstract

We report polarized neutron scattering measurements of the low energy spin fluctuations of the iron-selenide superconductor Li_0.8Fe_0.2ODFeSe below and above its superconducting transition temperatureT_c= 41 K. Our experiments confirmed that the resonance mode near 21 meV is magnetic. Moreover, the spin excitations are essentially isotropic in spin space at 5 ⩽E⩽ 29 meV in the superconducting and normal states. Our results suggest that the resonance mode in iron-based superconductors becomes isotropic when the influence of spin-orbit coupling and magnetic/nematic order is minimized, similar to those observed in cuprate superconductors.

Keywords: excitations; iron; magnetic; neutron; polarized; scattering.