Goldstein Moshe, Gefen Yuval
Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel.
Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
Phys Rev Lett. 2016 Dec 30;117(27):276804. doi: 10.1103/PhysRevLett.117.276804. Epub 2016 Dec 29.
Mach-Zehnder interferometry has been proposed as a probe for detecting the statistics of anyonic quasiparticles in fractional quantum Hall (FQH) states. Here, we focus on interferometers made of multimode edge states with upstream modes. We find that the interference visibility is suppressed due to downstream-upstream mode entanglement; the latter serves as a "which path" detector to the downstream interfering trajectories. Our analysis tackles a concrete realization of a filling factor of ν=2/3, but its applicability goes beyond that specific case, and encompasses the recent observation of the ubiquitous emergence of upstream neutral modes in FQH states. The latter, according to our analysis, goes hand in hand with the failure to observe Mach-Zehnder anyonic interference in fractional states. We point out how charge-neutral mode disentanglement will resuscitate the interference signal.
马赫-曾德尔干涉测量法已被提议作为一种探测器，用于检测分数量子霍尔（FQH）态中的任意子准粒子统计特性。在此，我们关注由具有上游模式的多模边缘态构成的干涉仪。我们发现，由于下游-上游模式纠缠，干涉可见度受到抑制；后者充当了下游干涉轨迹的“哪条路径”探测器。我们的分析针对填充因子ν = 2/3的具体实现情况，但它的适用性超出了该特定情形，涵盖了最近在FQH态中普遍出现上游中性模式的观测结果。根据我们的分析，后者与在分数态中未能观测到马赫-曾德尔任意子干涉密切相关。我们指出电荷中性模式解纠缠将如何恢复干涉信号。
