Fractional Quantum Hall States at Zero Magnetic Field
Fractional Quantum Hall States at Zero Magnetic Field
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DOI：
10.1103/physrevlett.106.236804
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发表时间：
2011-06-06
影响因子：
8.6
通讯作者：
Mudry, Christopher
中科院分区：
文献类型：
--
作者：
Neupert, Titus;Santos, Luiz;Mudry, Christopher
我们提出了一个简单的处方来平化具有非零陈氏数的孤立布洛赫带。我们首先表明，通过调整Haldane模型中最近邻和次近邻跳跃的比率，可以近似地平坦化具有非零陈恩数的带，类似地，在手性pi-通量方形晶格模型中也是如此。然后，我们证明了随着距离的增加而呈指数下降的距离跳跃可以达到完美的平坦化。最后，我们将相互作用添加到模型中，并给出了一个小系统在1/3填充时的精确对角化结果，这些结果支持(i)谱隙的存在，（ii）基态是拓扑态，（iii）霍尔电导是量子化的。
We present a simple prescription to flatten isolated Bloch bands with a nonzero Chern number. We first show that approximate flattening of bands with a nonzero Chern number is possible by tuning ratios of nearest-neighbor and next-nearest-neighbor hoppings in the Haldane model and, similarly, in the chiral-pi-flux square lattice model. Then we show that perfect flattening can be attained with further range hoppings that decrease exponentially with distance. Finally, we add interactions to the model and present exact diagonalization results for a small system at 1/3 filling that support (i) the existence of a spectral gap, (ii) that the ground state is a topological state, and (iii) that the Hall conductance is quantized.