TY  - JOUR
AU  - Song, Yu
AU  - Wang, Weiyi
AU  - S. Van Dyke, John
AU  - Pouse, Naveen
AU  - Ran, Sheng
AU  - Yazici, Duygu
AU  - Schneidewind, A.
AU  - Cermak, Petr
AU  - Qiu, Y.
AU  - Maple, M. B.
AU  - Morr, Dirk K.
AU  - Dai, Pengcheng
TI  - Nature of the spin resonance mode in CeCoIn5
JO  - Communications Physics
VL  - 3
IS  - 1
SN  - 2399-3650
CY  - London
PB  - Springer Nature
M1  - FZJ-2020-02173
SP  - 98
PY  - 2020
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000553489000002
DO  - DOI:10.1038/s42005-020-0365-8
UR  - https://juser.fz-juelich.de/record/877404
ER  -