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arXiv 1809.04776cond-mat.str-elcond-mat.dis-nn
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$ν=5/2$分数量子霍尔效应的无序驱动跃迁和中间相

Disorder-driven transition and intermediate phase for $ν=5/2$ fractional quantum Hall effect

W. Zhu, D. N. Sheng

摘要:

填充数为$ν=5/2$的分数量子霍尔效应是非阿贝尔拓扑序的主要候选者,而在随机无序存在下这种状态的命运尚未解决。在这里,我们解决这个悬而未决的问题,实现无偏诊断的基础上数值精确对角化。我们计算了无序平均霍尔电导和相关的拓扑不变陈数的统计分布,这明确地表征了无序驱动的坍缩的H2O H状态。当无序强度向临界值增加时,基于无序组态平均波函数保真度和纠缠熵检测到连续相变。在强无序制度,我们确定了一个复合费米液体(CFL)相与波动的陈数,在鲜明的对比,著名的$ν=1/3$的情况下,安德森绝缘体出现。有趣的是,最低的朗道水平投影的局域密度分布,波函数重叠,和纠缠熵作为无序强度的函数,同时信号的中间阶段,这可能是有关最近提出的Pfwean-anti-Pfweanpuddle状态。

英文摘要:

The fractional quantum Hall (FQH) effect at the filling number $ν=5/2$ is a primary candidate for non-Abelian topological order, while the fate of such a state in the presence of random disorder has not been resolved. Here, we address this open question by implementing unbiased diagnosis based on numerical exact diagonalization. We calculate the disorder averaged Hall conductance and the associated statistical distribution of the topological invariant Chern number, which unambiguously characterize the disorder-driven collapse of the FQH state. As the disorder strength increases towards a critical value, a continuous phase transition is detected based on the disorder configuration averaged wave function fidelity and the entanglement entropy. In the strong disorder regime, we identify a composite Fermi liquid (CFL) phase with fluctuating Chern numbers, in striking contrast to the well-known $ν=1/3$ case where an Anderson insulator appears. Interestingly, the lowest Landau level projected local density profile, the wavefunction overlap, and the entanglement entropy as a function of disorder strength simultaneously signal an intermediate phase, which may be relevant to the recent proposal of Pfaffian-anti-Pfaffian puddle state.

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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