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arXiv 0907.4023cond-mat.mes-hall
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各向异性Kagome晶格霍尔电导的量子相变

Quantum Phase Transition in Hall Conductivity on an Anisotropic Kagome Lattice

Shun-Li Yu, Jian-Xin Li, Li Sheng

摘要:

本文研究了Kagomé晶格上的量子霍尔效应。我们发现了一种新的QHE,其特征在于霍尔电导率的量子化规则$σ_{xy}=2ne^{2}/h$和朗道能级$E(n)=\pm v_{F}\sqrt{(n+1/2)\hbar Be}$($n$是一个整数),这是不同于任何已知的类型。在各向同性的情况下,该相从具有$σ_{xy}=4(n+1/2)e^{2}/h$和$E(n)=\pm v_{F}\sqrt{2n\hbar Be}$的QHE相演变而来,这在具有无质量狄拉克费米子的系统(例如石墨烯)中实现。相变并不像通常那样同时发生在所有的霍尔平台上,而是随着跳跃各向异性的增加,从低能量到高能量依次发生。

英文摘要:

We study the quantum Hall effect(QHE) on the Kagomé lattice with anisotropy in one of the hopping integrals. We find a new type of QHE characterized by the quantization rules for Hall conductivity $σ_{xy}=2ne^{2}/h$ and Landau Levels $E(n)=\pm v_{F}\sqrt{(n+1/2)\hbar Be}$ ($n$ is an integer), which is different from any known type. This phase evolves from the QHE phase with $σ_{xy}=4(n+1/2)e^{2}/h$ and $E(n)=\pm v_{F}\sqrt{2n\hbar Be}$ in the isotropic case, which is realized in a system with massless Dirac fermions (such as in graphene). The phase transition does not occur simultaneously in all Hall plateaus as usual but in sequence from low to high energies, with the increase of hopping anisotropy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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