中国物理B ›› 2024, Vol. 33 ›› Issue (6): 67601-067601.doi: 10.1088/1674-1056/ad3dce

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Low-energy spin dynamics in a Kitaev material Na3Ni2BiO6 investigated by nuclear magnetic resonance

Xinyu Shi(史昕雨)1,†, Yi Cui(崔祎)2,3,†, Yanyan Shangguan(上官艳艳)4,†, Xiaoyu Xu(徐霄宇)2, Zhanlong Wu(吴占龙)2, Ze Hu(胡泽)2, Shuo Li(李硕)2, Kefan Du(杜柯帆)2, Ying Chen(陈颖)2, Long Ma(马龙)5, Zhengxin Liu(刘正鑫)2,3, Jinsheng Wen(温锦生)4,6,‡, Jinshan Zhang(张金珊)1,§, and Weiqiang Yu(于伟强)2,3,¶   

  1. 1 Mathematics and Physics Department, North China Electric Power University, Beijing 102206, China;
    2 Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China;
    3 Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, China;
    4 National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China;
    5 Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China;
    6 Innovative Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
  • 收稿日期:2024-01-27 修回日期:2024-04-06 接受日期:2024-04-12 出版日期:2024-06-18 发布日期:2024-06-18
  • 通讯作者: Jinsheng Wen, Jinshan Zhang, Weiqiang Yu E-mail:jwen@nju.edu.cn;zhangjs@ncepu.edu.cn;wqyu_phy@ruc.edu.cn
  • 基金资助:
    vProject supported by the National Key R&D Program of China (Grant Nos. 2023YFA1406500, 2022YFA1402700, and 2021YFA1400400) and the National Natural Science Foundation of China (Grant Nos. 12134020, 12374156, 12104503, 12061131004, 12225407, and 12074174).

Low-energy spin dynamics in a Kitaev material Na3Ni2BiO6 investigated by nuclear magnetic resonance

Xinyu Shi(史昕雨)1,†, Yi Cui(崔祎)2,3,†, Yanyan Shangguan(上官艳艳)4,†, Xiaoyu Xu(徐霄宇)2, Zhanlong Wu(吴占龙)2, Ze Hu(胡泽)2, Shuo Li(李硕)2, Kefan Du(杜柯帆)2, Ying Chen(陈颖)2, Long Ma(马龙)5, Zhengxin Liu(刘正鑫)2,3, Jinsheng Wen(温锦生)4,6,‡, Jinshan Zhang(张金珊)1,§, and Weiqiang Yu(于伟强)2,3,¶   

  1. 1 Mathematics and Physics Department, North China Electric Power University, Beijing 102206, China;
    2 Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China;
    3 Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, China;
    4 National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China;
    5 Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China;
    6 Innovative Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
  • Received:2024-01-27 Revised:2024-04-06 Accepted:2024-04-12 Online:2024-06-18 Published:2024-06-18
  • Contact: Jinsheng Wen, Jinshan Zhang, Weiqiang Yu E-mail:jwen@nju.edu.cn;zhangjs@ncepu.edu.cn;wqyu_phy@ruc.edu.cn
  • Supported by:
    vProject supported by the National Key R&D Program of China (Grant Nos. 2023YFA1406500, 2022YFA1402700, and 2021YFA1400400) and the National Natural Science Foundation of China (Grant Nos. 12134020, 12374156, 12104503, 12061131004, 12225407, and 12074174).

摘要: We perform $^{23}$Na nuclear magnetic resonance (NMR) and magnetization measurements on an $S = 1$, quasi-2D honeycomb lattice antiferromagnet Na$_3$Ni$_2$BiO$_6$. A large positive Curie-Weiss constant of 22.9K is observed. The NMR spectra at low fields are consistent with a zigzag magnetic order, indicating a large easy-axis anisotropy. With the field applied along the $c^{*}$ axis, the NMR spectra confirm the existence of a $1/3$-magnetization plateau phase between 5.1T and 7.1T. The transition from the zigzag order to the $1/3$-magnetization plateau phase is also found to be a first-order type. A monotonic decrease of the spin gap is revealed in the $1/3$-magnetization plateau phase, which reaches zero at a quantum critical field $H_{\rm C}\approx8.35$T before entering the fully polarized phase. These data suggest the existence of exchange frustration in the system along with strong ferromagnetic interactions, hosting the possibility for Kitaev physics. Besides, well below the ordered phase, the 1/$T_1$ at high fields shows either a level off or an enhancement upon cooling below 3K, which suggests the existence of low-energy fluctuations.

关键词: one-third magnetization plateau phase, nuclear magnetic resonance, honeycomb-lattice antiferromagnet, Kitaev interaction

Abstract: We perform $^{23}$Na nuclear magnetic resonance (NMR) and magnetization measurements on an $S = 1$, quasi-2D honeycomb lattice antiferromagnet Na$_3$Ni$_2$BiO$_6$. A large positive Curie-Weiss constant of 22.9K is observed. The NMR spectra at low fields are consistent with a zigzag magnetic order, indicating a large easy-axis anisotropy. With the field applied along the $c^{*}$ axis, the NMR spectra confirm the existence of a $1/3$-magnetization plateau phase between 5.1T and 7.1T. The transition from the zigzag order to the $1/3$-magnetization plateau phase is also found to be a first-order type. A monotonic decrease of the spin gap is revealed in the $1/3$-magnetization plateau phase, which reaches zero at a quantum critical field $H_{\rm C}\approx8.35$T before entering the fully polarized phase. These data suggest the existence of exchange frustration in the system along with strong ferromagnetic interactions, hosting the possibility for Kitaev physics. Besides, well below the ordered phase, the 1/$T_1$ at high fields shows either a level off or an enhancement upon cooling below 3K, which suggests the existence of low-energy fluctuations.

Key words: one-third magnetization plateau phase, nuclear magnetic resonance, honeycomb-lattice antiferromagnet, Kitaev interaction

中图分类号:  (Nuclear magnetic resonance and relaxation)

  • 76.60.-k
75.30.Cr (Saturation moments and magnetic susceptibilities) 75.10.Jm (Quantized spin models, including quantum spin frustration) 64.70.Tg (Quantum phase transitions)