%0 Journal Article
%A Li, Yu
%A Yin, Zhiping
%A Liu, Zhonghao
%A Wang, Weiyi
%A Xu, Zhuang
%A Song, Yu
%A Tian, Long
%A Huang, Yaobo
%A Shen, Dawei
%A Abernathy, D. L.
%A Niedziela, J. L.
%A Ewings, R. A.
%A Perring, T. G.
%A Pajerowski, Daniel M.
%A Matsuda, Masaaki
%A Bourges, Philippe
%A Mechthild, Enderle
%A Su, Yixi
%A Dai, Pengcheng
%T Coexistence of Ferromagnetic and Stripe Antiferromagnetic Spin Fluctuations in SrCo$_2$As$_2$
%J Physical review letters
%V 122
%N 11
%@ 1079-7114
%C College Park, Md.
%I APS
%M FZJ-2019-02129
%P 117204
%D 2019
%X We use inelastic neutron scattering to study energy and wave vector dependence of spin fluctuations in SrCo2As2, derived from SrFe2−xCoxAs2 iron pnictide superconductors. Our data reveal the coexistence of antiferromagnetic (AF) and ferromagnetic (FM) spin fluctuations at wave vectors QAF=(1,0) and QFM=(0,0)/(2,0), respectively. By comparing neutron scattering results with those of dynamic mean field theory calculation and angle-resolved photoemission spectroscopy experiments, we conclude that both AF and FM spin fluctuations in SrCo2As2 are closely associated with a flatband of the eg orbitals near the Fermi level, different from the t2g orbitals in superconducting SrFe2−xCoxAs2. Therefore, Co substitution in SrFe2−xCoxAs2 induces a t2g to eg orbital switching, and is responsible for FM spin fluctuations detrimental to the singlet pairing superconductivity.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:30951336
%U <Go to ISI:>//WOS:000461923000010
%R 10.1103/PhysRevLett.122.117204
%U https://juser.fz-juelich.de/record/861696