Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu2IrO3
Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu2IrO3
复制标题
DOI：
10.1103/physrevlett.122.167202
复制
发表时间：
2019-04-26
影响因子：
8.6
通讯作者：
Choi, Kwang-Yong
中科院分区：
文献类型：
--
作者：
Choi, Y. S.;Lee, C. H.;Choi, Kwang-Yong
本文报道了Kitaev蜂窝状铱酸盐Cu_2IrO_3淬灭无序样品的磁化强度M（H）、直流和交流磁化率chi（T）、比热C-m（T）和μ子自旋弛豫（μ SR）的测量结果。尽管存在化学障碍，但我们从C-m（T）和μ SR数据中没有发现自旋玻璃低至260 mK的迹象。此外，通过零场μ子自旋弛豫观察到的持续自旋动力学证明了静态磁性的存在。值得注意的观察是HIT中chi[H，7]和M[H，T]的标度关系，标度指数α = 0.26-0.28，预期来自键随机性。然而，C-m[H，T]/T不服从预测的普遍标度律，指向存在额外的低位激发的背景下的键无序自旋液体。我们的结果表明，淬火无序的Kitaev自旋系统，由于其独特的键字符的多方面的影响。
We report on magnetization M(H), dc and ac magnetic susceptibility chi(T), specific heat C-m(T) and muon spin relaxation (mu SR) measurements of the Kitaev honeycomb iridate Cu2IrO3 with quenched disorder. In spite of the chemical disorders, we find no indication of spin glass down to 260 mK from the C-m(T) and mu SR data. Furthermore, a persistent spin dynamics observed by the zero-field muon spin relaxation evidences an absence of static magnetism. The remarkable observation is a scaling relation of chi[H,7] and M[H, T] in HIT with the scaling exponent alpha = 0.26-0.28, expected from bond randomness. However, C-m[H, T]/T disobeys the predicted universal scaling law, pointing towards the presence of additional low-lying excitations on the background of bond-disordered spin liquid. Our results signify a many-faceted impact of quenched disorder in a Kitaev spin system due to its peculiar bond character.