Fractional quantum-Hall liquid spontaneously generated by strongly correlated t(2g) electrons.
Fractional quantum-Hall liquid spontaneously generated by strongly correlated t(2g) electrons.
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强相关 t(2g) 电子自发产生的分数量子霍尔液体
DOI：
10.1103/physrevlett.108.126405
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发表时间：
2012
影响因子：
8.6
通讯作者：
M. Daghofer
中科院分区：
文献类型：
--
作者：
J. W. F. Venderbos;S. Kourtis;J. van den Brink;M. Daghofer
对于拓扑非平凡和非常窄的带，电子之间的库仑排斥已经被预测在没有磁场的情况下会产生自发的分数量子霍尔（Fractional quantum-Hall，简称FWHH）态。在这里，我们表明，强关联的电子在a轨道系统的三角形晶格自组织成自旋手征磁有序模式，精确地诱导所需的拓扑非平凡的和平坦的带。这种行为非常健壮，不依赖于微调。为了超越平均场并研究长程相互作用的影响，我们将低能电子态映射到有效的单带模型上。精确对角化，然后用于建立一个自发的的BAROH状态的签名。
For topologically nontrivial and very narrow bands, Coulomb repulsion between electrons has been predicted to give rise to a spontaneous fractional quantum-Hall (FQH) state in the absence of magnetic fields. Here we show that strongly correlated electrons in a-orbital system on a triangular lattice self-organize into a spin-chiral magnetic ordering pattern that induces precisely the required topologically nontrivial and flat bands. This behavior is very robust and does not rely on fine-tuning. In order to go beyond mean field and to study the impact of longer-range interactions, we map the low-energy electronic states onto an effective one-band model. Exact diagonalization is then used to establish signatures of a spontaneous FQH state.