kagome晶格中无序和自旋交换作用对量子霍尔电导率的影响
PDF下载 (270)胡凌志,商敬龙,江红民.kagome晶格中无序和自旋交换作用对量子霍尔电导率的影响[J].宁波大学学报(理工版),2021,34(5):55-60.DOI:
HU Lingzhi,SHANG Jinglong,JIANG Hongmin.Influence of disorder and spin exchange interaction on quantum Hall conductivity in kagome lattice[J].Journal of Ningbo University(Natural Science & Engineering Edition),2021,34(5):55-60.DOI:
| Title: | Influence of disorder and spin exchange interaction on quantum Hall conductivity in kagome lattice |
| 作者: | 胡凌志, 商敬龙, 江红民 |
| Author(s): | HU Lingzhi, SHANG Jinglong, JIANG Hongmin |
| 关键词: | 量子霍尔效应; 量子自旋液体; 无序; 自旋交换相互作用 |
| Keywords: | quantum Hall effect; quantum spin liquid; disorder; spin exchange interaction |
| 分类号: | O469 |
| 文献标识码: | A |
| 摘要: | 数值计算了kagome晶格中无序和海森堡交换相互作用下的量子霍尔效应, 其中无序包括非磁性杂质和磁性杂质, 相互作用包括近邻的铁磁和反铁磁海森堡交换相互作用. 计算结果表明, 非磁性和磁性无序增强将导致量子化的霍尔电导平台从高朗道能级到低朗道能级逐步被破坏. 除了破坏霍尔电导平台, 磁性杂质还可以解除自旋简并, 使系统发生从非常规量子霍尔效应到常规量子霍尔效应的转变. 对于自旋交换作用影响下的霍尔电导, 铁磁相互作用同样会使系统发生从非常规量子霍尔效应到常规量子霍尔效应的转变, 而反铁磁相互作用却对系统的量子霍尔电导没有影响. 这暗示着在S=1/2的反铁磁kagome体系中形成的量子自旋液体仍然保有零能隙的特征. |
| Abstract: | The quantum Hall effect under the disorder and Heisenberg exchange interaction in kagome lattices are numerically calculated. The disorder includes non-magnetic impurities and magnetic impurities, and the interaction contains the nearby ferromagnetic and antiferromagnetic Heisenberg exchange interactions. The calculated results show that the enhancement of non-magnetic and magnetic disorder will cause the quantized Hall conductance platform to be gradually destroyed from the high Landau energy level to the low Landau energy level. Except for destroying the Hall conductivity platform, magnetic impurities can also lift spin degeneration, causing the system to undergo a transition from an unconventional quantum Hall effect to a conventional one. For the Hall conductance under the influence of Heisenberg spin exchange interactions, the ferromagnetic interaction will also trigger the system to undergo a transition from unconventional quantum Hall effect to conventional one, while antiferromagnetic interaction has no effect on the quantum Hall conductivity. This implies that the quantum spin liquid formed in the S=1/2 antiferromagnetic kagome system still retains the characteristic of zero energy gap. |
| 参考文献 /References: | [1] Castro Neto A H, Guinea F, Peres N M R, et al. The electronic properties of graphene[J]. Reviews of Modern Physics, 2009, 81(1):109. [2] Sachdev S. Kagomé- and triangular-lattice Heisenberg antiferromagnets: Ordering from quantum fluctuations and quantum-disordered ground states with unconfined bosonic spinons[J]. Physical Review B, 1992, 45(21): 12377-12396. [3] Gotze O, Farnell D J J, Bishop R F, et al. Heisenberg antiferromagnet on the kagome lattice with arbitrary spin: A higher-order coupled cluster treatment[J]. Physical Review B, 2011, 84(22):224428. [4] Jiang H C, Weng Z Y, Sheng D N. Density matrix renormalization group numerical study of the kagome antiferromagnet[J]. Physical Review Letters, 2008, 101(11):117203. [5] Yan S, Huse D A, White S R. Spin-liquid ground state of the S=1/2 kagome Heisenberg antiferromagnet[J]. Science, 2011, 332(6034):1173-1176. [6] Depenbrock S, McCulloch I P, Schollwock U. Nature of the spin-liquid ground state of the S=1/2 Heisenberg model on the kagome lattice[J]. Physical Review Letters, 2012, 109(6):067201. [7] Jiang H C, Wang Z H, Balents L. Identifying topological order by entanglement entropy[J]. Nature Physics, 2012, 8:902-905. [8] Nishimoto S, Shibata N, Hotta C. Controlling frustrated liquids and solids with an applied field in a kagome Heisenberg antiferromagnet[J]. Nature Communications, 2013, 4:2287. [9] Mei J W, Chen J Y, He H, et al. Gapped spin liquid with Z2 topological order for kagome Heisenberg model[J]. Physical Review B, 2017, 95(23):235107. [10] Sindzingre P, Lhuillier C. Low-energy excitations of the kagomé antiferromagnet and the spin-gap issue[J]. Europhysics Letters, 2009, 88(2):27009. [11] Lauchli A M, Sudan J, Moessner R. The S=1/2 kagome Heisenberg antiferromagnet revisited[J]. Physical Review B, 2019, 100(15):155142. [12] Ran Y, Hermele M, Lee P A, et al. Projected-wave- function study of the spin-1/2 Heisenberg model on the kagome lattice[J]. Physical Review Letters, 2007, 98(11): 117205. [13] Iqbal Y, Becca F, Sorella S, et al. Gapless spin-liquid phase in the kagome spin-1/2 Heisenberg antiferromagnet [J]. Physical Review B, 2013, 87(6):060405. [14] Iqbal Y, Poilblanc D, Sorella S, et al. Spin-1/2 Heisenberg J1?J2 antiferromagnet on the kagome lattice[J]. Physical Review B, 2015, 91(2):020402. [15] Liao H J, Xie Z Y, Chen J, et al. Gapless spin-liquid ground state in the S=1/2 kagome antiferromagnet[J]. Physical Review Letters, 2017, 118(13):137202. [16] Laughlin R B. Quantized Hall conductivity in two dimensions[J]. Physical Review B, 1981, 23(10):5632(R). [17] Sheng D N, Weng Z Y. Disappearance of integer quantum Hall effect[J]. Physical Review Letters, 1997, 78(2):318- 321. [18] Sheng D N, Sheng L, Weng Z Y. Quantum Hall effect in graphene: Disorder effect and phase diagram[J]. Physical Review B, 2006, 73(23):233406. [19] Lachman E O, Young A F, Richardella A, et al. Visualization of superparamagnetic dynamics in magnetic topological insulators[J]. Science Advances, 2015, 1(10): e1500740. [20] Yasuda K, Mogi M, Yoshimi R, et al. Quantized chiral edge conduction on domain walls of a magnetic topological insulator[J]. Science, 2017, 358(6368):1311- 1314. [21] Yu S L, Li J X, Li S. Quantum phase transition in Hall conductivity on an anisotropic kagome lattice[J]. Physical Review B, 2009, 80(19):193304. |
| 备注/Memo: | 收稿日期: 2021－03－20. 宁波大学学报（理工版）网址: http://journallg.nbu.edu.cn/ 基金项目: 国家自然科学基金（11574069）. 第一作者: 胡凌志（1996－）, 男, 江西抚州人, 在读硕士研究生, 主要研究方向: 凝聚态理论. E-mail: 1479506332@qq.com *通信作者: 江红民（1976－）, 男, 河南内黄人, 教授, 主要研究方向: 高温超导和强关联电子系统. E-mail: monsoonjhm@sina.com 宁波大学学报（理工版）网址：http://journallg.nbu.edu.cn/ |
