发表机构
Institut für Theoretische Physik, Universität Leipzig（莱比锡大学理论物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过开放量子点中的共隧穿干涉仪，利用非平衡Keldysh计算提取任意子交换相位，为分数量子霍尔态统计提供稳健测量方案。
AI 中文摘要
分数量子霍尔态的基本激发服从任意子统计，其交换相位$\theta$介于玻色子与费米子值之间。我们研究了一种干涉仪，其中三个手性边缘段通过三个量子点接触两两相连，使得根据所施加的电压，其中一个段充当开放量子点：其谱是连续的，并且通过它的隧穿无需任何栅极调谐即可共振。该装置以特别简单的方式实现了最近提出的反点干涉仪的共隧穿机制。利用非平衡Keldysh计算至隧穿振幅的三阶，我们表明干涉电流包含一个共隧穿贡献，其中两个准粒子被交换，因此对于Laughlin态，交换相位$\theta=\pi\nu$作为在两种电压配置下测量的阿哈罗诺夫-玻姆振荡之间的相移出现。我们获得了在有限温度和量子点接触之间有限间距下干涉电流的闭合解析表达式，并表明，只要电压引起的封闭面积变化被充分屏蔽，交换相位可以从稳健的相位平台差中提取。或者，在两个漏极同时测量干涉电流可以避免这种屏蔽假设，并且飞行时间相位可以解析量化，从而通过受控外推以百分之几的系统误差提取交换相位。
英文摘要
The elementary excitations of fractional quantum Hall states obey anyonic statistics, described by an exchange phase $θ$ intermediate between the bosonic and fermionic values. We study an interferometer in which three chiral edge segments are pairwise connected by three quantum point contacts, so that, depending on the applied voltages, one of the segments acts as an open quantum dot: its spectrum is continuous, and tunneling through it is resonant without any gate tuning. This setup realizes the co-tunneling mechanism of a recently proposed antidot interferometer in a particularly simple setting. Using a non-equilibrium Keldysh calculation to third order in the tunneling amplitudes, we show that the interference current contains a co-tunneling contribution in which two quasiparticles are exchanged, so that for Laughlin states the exchange phase $θ=πν$ appears as the phase shift between the Aharonov-Bohm oscillations measured in two voltage configurations. We obtain a closed analytic expression for the interference current at finite temperature and finite separation between the quantum point contacts and show that, provided voltage-induced changes of the enclosed area are sufficiently screened, the exchange phase can be extracted from a robust phase-plateau difference. Alternatively, simultaneous measurements of the interference currents at two drains avoid this screening assumption and time-of-flight phases can be quantified analytically, allowing the exchange phase to be extracted by a controlled extrapolation with a few-percent systematic error.
Comments17 pages, 6 figures
