%0 Journal Article
%A He, Zheng
%A Wang, Qisi
%A Feng, Yu
%A Kim, Chul
%A Kyung, Wonshik
%A Kim, Changyoung
%A Wo, Hongliang
%A Ding, Gaofeng
%A Hao, Yiqing
%A Liu, Feiyang
%A Walker, Helen C.
%A Adroja, Devashibhai T.
%A Schneidewind, Astrid
%A Wang, Wenbin
%A Zhao, Jun
%T Spin fluctuations in Sr 1.8 La 0.2 RuO 4
%J Physical review / B
%V 107
%N 20
%@ 2469-9950
%C Woodbury, NY
%I Inst.
%M FZJ-2023-02082
%P L201107
%D 2023
%X We use inelastic neutron scattering to study spin fluctuations in Sr1.8La0.2RuO4, where Lanthanum doping triggers a Lifshitz transition by pushing the van Hove singularity in the γ band to the Fermi energy. Strong spinfluctuations emerge at an incommensurate wave vector Qic = (0.3, 0.3), corresponding to the nesting vector between α and β Fermi sheets. The incommensurate antiferromagnetic fluctuations shift toward (0.25,0.25) with increasing energy up to ∼110 meV. By contrast, scatterings near the ferromagnetic wave vectors Q = (1, 0) and (1,1) remain featureless at all energies. This contradicts the weak-coupling perspective that suggests a sharpenhancement of ferromagnetic susceptibility due to the divergence of density of states in the associated γ band. Our findings imply that ferromagnetic fluctuations in Sr2RuO4 and related materials do not fit into the weakcoupling paradigm, but instead are quasilocal fluctuations induced by Hund’s coupling. This imposes significant constraints for the pairing mechanism involving spin fluctuations.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000993596700003
%R 10.1103/PhysRevB.107.L201107
%U https://juser.fz-juelich.de/record/1007492