NMR evidence of charge fluctuations in multiferroic CuBr<sub>2</sub>

NMR evidence of charge fluctuations in multiferroic CuBr₂

Wang Rui-Qi^{1, 2}, Zheng Jia-Cheng², Chen Tao², Wang Peng-Shuai², Zhang Jin-Shan³, Cui Yi², Wang Chao⁴, Li Yuan⁴, Xu Sheng^{1, †}, Yuan Feng^{1, ‡}, Yu Wei-Qiang²

(color online) (a) The NQR spectra of ⁷⁹Br and ⁸¹Br, at typical temperatures above T_N. Data are offset for clarity. (b) The ν Q 79 and ν Q 81 as functions of temperature determined by the NQR measurement above T_N.