Magnetic ground state of FeSe

Qisi Wang; Yao Shen; Bingying Pan; Xiaowen Zhang; K. Ikeuchi; K. Iida; A. D. Christianson; H. C. Walker; D. T. Adroja; M. Abdel-Hafiez; Xiaojia Chen; D. A. Chareev; A. N. Vasiliev; Jun Zhao

doi:10.1038/ncomms12182

arXiv · 1511.02485

Magnetic ground state of FeSe

Qisi Wang·Yao Shen·Bingying Pan·Xiaowen Zhang·K. Ikeuchi·K. Iida·A. D. Christianson·H. C. Walker·D. T. Adroja·M. Abdel-Hafiez·Xiaojia Chen·D. A. Chareev·A. N. Vasiliev·Jun Zhao

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Abstract

Elucidating the nature of the magnetism of a high-temperature superconductor is crucial for establishing its pairing mechanism. The parent compounds of the cuprate and iron-pnictide superconductors exhibit N\'eel and stripe magnetic order, respectively. However, FeSe, the structurally simplest iron-based superconductor, shows nematic order (Ts = 90 K), but not magnetic order in the parent phase, and its magnetic ground state is intensely debated. Here, we report inelastic neutron-scattering experiments that reveal both stripe and N\'eel spin fluctuations over a wide energy range at 110 K. On entering the nematic phase, a substantial amount of spectral weight is transferred from the N\'eel to the stripe spin fluctuations. Moreover, the total fluctuating magnetic moment of FeSe is ~ 60% larger than that in the iron pnictide BaFe2As2. Our results suggest that FeSe is a novel S = 1 nematic quantum-disordered paramagnet interpolating between the N\'eel and stripe magnetic instabilities.

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Qisi Wang, Yao Shen, Bingying Pan, Xiaowen Zhang, K. Ikeuchi, K. Iida, A. D. Christianson, H. C. Walker, D. T. Adroja, M. Abdel-Hafiez, Xiaojia Chen, D. A. Chareev, A. N. Vasiliev, Jun Zhao. 2015-11-08. Magnetic ground state of FeSe. https://doi.org/10.1038/ncomms12182

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