Low-Energy Spin Excitations in Detwinned FeSe  

作　　者：刘瑞鲜 Mitsutaka Nakamura Kazuya Kamazawa 鲁兴业 Ruixian Liu;Mitsutaka Nakamura;Kazuya Kamazawa;Xingye Lu(Center for Advanced Quantum Studies,School of Physics and Astronomy,Beijing Normal University,Beijing 100875,China;J-PARC Center,Japan Atomic Energy Agency(JAEA),Tokai,Ibaraki 319-1195,Japan;Research Center for Neutron Science and Technology,Comprehensive Research Organization for Science and Society,Tokai,Ibaraki 319-1106,Japan)

机构地区：[1]Center for Advanced Quantum Studies,School of Physics and Astronomy,Beijing Normal University,Beijing 100875,China [2]J-PARC Center,Japan Atomic Energy Agency(JAEA),Tokai,Ibaraki 319-1195,Japan [3]Research Center for Neutron Science and Technology,Comprehensive Research Organization for Science and Society,Tokai,Ibaraki 319-1106,Japan

出　　处：《Chinese Physics Letters》2024年第6期112-118,共7页中国物理快报（英文版）

基　　金：Beijing Normal University was supported by the Fundamental Research Funds for the Central Universities;the National Key Projects for Research and Development of China(No.2021YFA1400400);the National Natural Science Foundation of China(Grant Nos.12174029 and 11922402);the neutron beamtimes from J-PARC(Proposal No.2019A0002)。

摘　　要：Antiferromagnetic spin fluctuation is regarded as the leading driving force for electron pairing in high-Tc superconductors.In iron-based superconductors,spin excitations at low energy range,especially the spin-resonance mode at ER~5kBTc,are important for understanding the superconductivity.Here,we use inelastic neutron scattering(INS)to investigate the symmetry and in-plane wave-vector dependence of low-energy spin excitations in uniaxial-strain detwinned Fe Se.The low-energy spin excitations(E<10 meV)appear mainly at Q=(±1,0)in the superconducting state(T9K)and the nematic state(T90 K),confirming the constant C_(2) rotational symmetry and ruling out the C_(4) mode at E≈3 meV reported in a prior INS study.Moreover,our results reveal an isotropic spin resonance in the superconducting state,which is consistent with the s±wave pairing symmetry.At slightly higher energy,low-energy spin excitations become highly anisotropic.The full width at half maximum of spin excitations is elongated along the transverse direction.The Q-space isotropic spin resonance and highly anisotropic low-energy spin excitations could arise from dyz intra-orbital selective Fermi surface nesting between the hole pocket aroundΓpoint and the electron pockets centered at MX point.

关 键 词：EXCITATION SYMMETRY slightly 

分 类 号：O469[理学—凝聚态物理]