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arXiv 2201.12169cond-mat.mes-hallcond-mat.str-el
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量子霍尔相位和分数量子霍尔相位中的边缘重构和涌现中性模

Edge Reconstruction and Emergent Neutral Modes in Integer and Fractional Quantum Hall Phases

Udit Khanna, Moshe Goldstein, Yuval Gefen

摘要:

本文包括我们最近的工作,分数手征模出现由于整数和分数量子霍尔(QH)相位的边缘重建。新增加的部分是对$ν= 2/5$相位的边缘重建的分析。QH态是物质的拓扑相,其特征在于边缘处的手征无隙模式。这些边缘模式可以向下游或上游传播,并且可以支持电荷或电荷中性激发。从拓扑考虑,粒子状QH状态预计只支持下游电荷模式。然而,电子排斥和边界限制势之间的相互作用可以驱动在边缘处的某些量子相变(称为重构),这与额外的成对反向传播模式的成核相关联。采用变分方法,在这里,我们研究了边缘重建的原型粒子状相位在$ν= 1, 1/3$和$2/5$作为一个函数的斜率的限制势。我们的分析表明,随后的重整化的边缘模式,驱动的无序诱导隧穿和模间相互作用,可能会导致上游中性模式的出现。这些预测可以在适当设计的传输实验中进行测试。我们的研究结果也与以前的观察上游中性模式在这些QH阶段,并可以解释电子马赫-曾德尔设置中没有任何干扰。

英文摘要:

This paper comprises a review of our recent works on fractional chiral modes that emerge due to edge reconstruction in integer and fractional quantum Hall (QH) phases. The new part added is an analysis of edge reconstruction of the $ν= 2/5$ phase. QH states are topological phases of matter featuring chiral gapless modes at the edge. These edge modes may propagate downstream or upstream, and may support either charge or charge-neutral excitations. From topological considerations, particle-like QH states are expected to support only downstream charge modes. However the interplay between the electronic repulsion and the boundary confining potential may drive certain quantum phase transitions (called reconstructions) at the edge, which are associated to the nucleation of additional pairs of counter-propagating modes. Employing variational methods, here we study edge reconstruction in the prototypical particle-like phases at $ν= 1, 1/3$ and $2/5$ as a function of the slope of the confining potential. Our analysis shows that subsequent renormalization of the edge modes, driven by disorder-induced tunnelling and intermode interactions, may lead to the emergence of upstream neutral modes. These predictions may be tested in suitably designed transport experiments. Our results are also consistent with previous observations of upstream neutral modes in these QH phases, and could explain the absence of anyonic interference in electronic Mach-Zehnder setups.

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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