TY  - JOUR
AU  - Ran, Kejing
AU  - Wang, Jinghui
AU  - Bao, Song
AU  - Cai, Zhengwei
AU  - Shangguan, Yanyan
AU  - Ma, Zhen
AU  - Wang, Wei
AU  - Dong, Zhao-Yang
AU  - Cermak, P.
AU  - Schneidewind, A.
AU  - Meng, Siqin
AU  - Lu, Zhilun
AU  - Yu, Shun-Li
AU  - Li, Jian-Xin
AU  - Wen, Jinsheng
TI  - Evidence for Magnetic Fractional Excitations in a Kitaev Quantum-Spin-Liquid Candidate α-RuCl3
JO  - Chinese physics letters
VL  - 39
SN  - 0256-307X
CY  - Bristol
PB  - IOP Publ.
M1  - FZJ-2021-06214
SP  - 027501
PY  - 2022
AB  - It is known that 𝛼-RuCl3 has been studied extensively because of its proximity to the Kitaev quantum-spin-liquid(QSL) phase and the possibility of approaching it by tuning the competing interactions. Here we present the firstpolarized inelastic neutron scattering study on 𝛼-RuCl3 single crystals to explore the scattering continuum aroundthe 𝛤 point at the Brillouin zone center, which was hypothesized to be resulting from the Kitaev QSL state butwithout concrete evidence. With polarization analyses, we find that, while the spin-wave excitations around the𝑀 point vanish above the transition temperature 𝑇N, the pure magnetic continuous excitations around the 𝛤point are robust against temperature. Furthermore, by calculating the dynamical spin-spin correlation functionusing the cluster perturbation theory, we derive magnetic dispersion spectra based on the 𝐾–𝛤 model, whichinvolves with a ferromagnetic Kitaev interaction of −7.2meV and an off-diagonal interaction of 5.6 meV. We findthis model can reproduce not only the spin-wave excitation spectra around the 𝑀 point, but also the non-spinwavecontinuous magnetic excitations around the 𝛤 point. These results provide evidence for the existence offractional excitations around the 𝛤 point originating from the Kitaev QSL state, and further support the validityof the 𝐾–𝛤 model as the effective minimal spin model to describe 𝛼-RuCl3.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000752027200001
DO  - DOI:10.1088/0256-307X/39/2/027501
UR  - https://juser.fz-juelich.de/record/904645
ER  -