TY  - JOUR
AU  - Ma, Zhen
AU  - Dong, Zhao-Yang
AU  - Wang, Jinghui
AU  - Zheng, Shuhan
AU  - Ran, Kejing
AU  - Bao, Song
AU  - Cai, Zhengwei
AU  - Shangguan, Yanyan
AU  - Wang, Wei
AU  - Boehm, M.
AU  - Steffens, P.
AU  - Regnault, L.-P.
AU  - Wang, Xiao
AU  - Su, Yixi
AU  - Yu, Shun-Li
AU  - Liu, Jun-Ming
AU  - Li, Jian-Xin
AU  - Wen, Jinsheng
TI  - Disorder-induced broadening of the spin waves in the triangular-lattice quantum spin liquid candidate YbZnGaO$_4$
JO  - Physical review / B
VL  - 104
IS  - 22
SN  - 1098-0121
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2022-00277
SP  - 224433
PY  - 2021
AB  - Disorder is important in the study of quantum spin liquids, but its role on the spin dynamics remains elusive. Here, we explore the disorder effect by investigating the magnetic-field dependence of the low-energy magnetic excitations in a triangular-lattice frustrated magnet YbZnGaO4 with inelastic neutron scattering. With an intermediate field of 2.5 T applied along the c axis, the broad continuum at zero field becomes more smeared both in energy and momentum. With a field up to 10 T, which fully polarizes the magnetic moments, we observe clear spin-wave excitations with a gap of ∼1.4meV comparable to the bandwidth. However, the spectra are significantly broadened. The excitation spectra both at zero and high fields can be reproduced by performing classical Monte Carlo simulations which take into account the disorder effect arising from the random site mixing of nonmagnetic Zn2+ and Ga3+ ions. These results elucidate the critical role of disorder in broadening the magnetic excitation spectra and mimicking the spin-liquid features in frustrated quantum magnets.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000753768800005
DO  - DOI:10.1103/PhysRevB.104.224433
UR  - https://juser.fz-juelich.de/record/904963
ER  -