Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu2IrO3

被引:59
作者
Choi, Y. S. [1 ]
Lee, C. H. [1 ]
Lee, S. [1 ]
Yoon, Sungwon [1 ]
Lee, W. -J. [1 ]
Park, J. [1 ]
Ali, Anzar [2 ]
Singh, Yogesh [2 ]
Orain, Jean-Christophe [3 ]
Kim, Gareoung [4 ]
Rhyee, Jong-Soo [4 ]
Chen, Wei-Tin [5 ]
Chou, Fangcheng [5 ,6 ,7 ]
Choi, Kwang-Yong [1 ]
机构
[1] Chung Ang Univ, Dept Phys, Seoul 06974, South Korea
[2] Indian Inst Sci Educ & Res Mohali, Dept Phys Sci, Sect 81, Sas Nagar 140306, Manauli, India
[3] Paul Scherrer Inst, Lab Muon Spin Spect, CH-5232 Villigen, Switzerland
[4] Kyung Hee Univ, Dept Appl Phys, Yongin 17104, South Korea
[5] Natl Taiwan Univ, Ctr Condensed Matter Sci, Taipei 10617, Taiwan
[6] Natl Synchrotron Radiat Res Ctr, Hsinchu 30076, Taiwan
[7] Minist Sci & Technol, Taiwan Consortium Emergent Crystalline Mat, Taipei 10622, Taiwan
关键词
SPIN; LIQUID;
D O I
10.1103/PhysRevLett.122.167202
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
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.
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页数:5
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