%0 Journal Article
%A Song, Yu
%A Wang, Weiyi
%A S. Van Dyke, John
%A Pouse, Naveen
%A Ran, Sheng
%A Yazici, Duygu
%A Schneidewind, A.
%A Cermak, Petr
%A Qiu, Y.
%A Maple, M. B.
%A Morr, Dirk K.
%A Dai, Pengcheng
%T Nature of the spin resonance mode in CeCoIn5
%J Communications Physics
%V 3
%N 1
%@ 2399-3650
%C London
%I Springer Nature
%M FZJ-2020-02173
%P 98
%D 2020
%X Spin-fluctuation-mediated unconventional superconductivity can emerge at the border of magnetism, featuring a superconducting order parameter that changes sign in momentum space. Detection of such a sign-change is experimentally challenging, since most probes are not phase-sensitive. The observation of a spin resonance mode (SRM) from inelastic neutron scattering is often seen as strong phase-sensitive evidence for a sign-changing superconducting order parameter, by assuming the SRM is a spin-excitonic bound state. Here we show that for the heavy fermion superconductor CeCoIn5, its SRM defies expectations for a spin-excitonic bound state, and is not a manifestation of sign-changing superconductivity. Instead, the SRM in CeCoIn5 likely arises from a reduction of damping to a magnon-like mode in the superconducting state, due to its proximity to magnetic quantum criticality. Our findings emphasize the need for more stringent tests of whether SRMs are spin-excitonic, when using their presence to evidence sign-changing superconductivity.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000553489000002
%R 10.1038/s42005-020-0365-8
%U https://juser.fz-juelich.de/record/877404