发表机构
University of Geneva（日内瓦大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出用三路径分数量子霍尔干涉仪测试边缘手性，通过三个相干QPC形成磁通包围环，利用直接传输与两步路径干涉解决上下游传播问题，可提取准粒子电荷、缩放维度和交换角等，实现对阿贝尔边缘定向内容的探测。
AI 中文摘要
我们提出了一种用于分数量子霍尔边缘定向因果响应的平均电流干涉仪。三个相干量子点接触（QPC）形成一个磁通包围环，因此主导的阿哈罗诺夫 - 玻姆谐波在隧穿中是三次方的。直接传输和相干两步路径之间的干涉解决了下游和上游传播。对于$\nu = 1/m$的局部劳克林边缘，上游系数恰好消失，而下游幅度按$E^{3\nu - 2}$缩放。跨越隧穿点的弱有限范围非局部密度相互作用激活了上游系数而不产生上游模式。在低温和未分辨延迟下，其幅度按$E^{2\nu - 1}$缩放，并且相对于下游参考的对齐相位为$-\pi(1 - \nu)/2+\chi_a$模$2\pi$，其中$\chi_a = 0$或$\pi$。相反的循环电压排序隔离两个方向，而具有中性弱链接的折叠同填充劳克林边缘实现了符号可调桥。对于一般阿贝尔边缘，该装置探测所选隧穿顶点的定向内容。如果$\delta_\pm$是其下游和上游权重，其非零定向幅度按$E^{3\Delta_\ell - 2}$缩放，其中$\Delta_\ell=\delta_++\delta_-$，并服从$A^u_\ell/A^d_\ell=|\sin(\pi\delta_-)/\sin(\pi\delta_+)|$。当两者都非零时，正磁通对齐在去除已知固定符号后给出相对相位$\pi\Delta_\ell = 2\pi h_\ell$。在同顶点相干未分辨飞行区域中，缩放维度和定向比确定交换角$\theta_\ell=\pi(\delta_+-\delta_-)$模$2\pi$。阿哈罗诺夫 - 玻姆磁通频率还给出电荷，从而能够单独提取准粒子电荷、缩放维度和交换角。
英文摘要
An upstream neutral mode can influence quasiparticle tunneling even when electric charge propagates only downstream. We propose a three-path fractional quantum Hall interferometer that probes this directional structure through the flux dependence of average terminal currents. Interference between direct and two-step tunneling first contributes at cubic order in the tunneling amplitudes of three weak quantum point contacts. In the local theory, equal drain voltages separate the downstream and upstream responses: for a purely downstream tunneling excitation, the cubic fundamental Aharonov-Bohm harmonic vanishes at one drain, while the other remains bright. Averaging measurements with exchanged unequal drain voltages extends this separation to a configuration in which all contacts are biased. It requires independent calibration of the electrostatic phase shift and fixed or known tunneling magnitudes. For a selected Abelian excitation with two-point correlation exponent $0<Δ_{\boldsymbol{\ell}}<1$, the common low-temperature bias power and directional amplitude ratio determine its scaling dimension and principal exchange angle. We also show that a weak static density interaction spanning two tunneling points can activate the dark harmonic without adding an upstream mode. In the high-bias static limit, the first-order Laughlin activated amplitude scales as $E^{2ν-1}$, where $E$ is the source-drain bias energy and $ν$ is the filling factor. In the weak localized single-mode infrared regime, the bright harmonic retains its leading scaling and can serve as a reference in the same device. The calculation assumes one coherent tunneling species and common-temperature edge correlations with unresolved propagation times.
Comments21 pages, 3 figures. Substantially revised: corrected cubic terminal-current calculation; chirality test reformulated using equal and exchanged drain voltages; exchange-angle extraction clarified; nonlocal-interaction analysis and appendices revised
