以色列魏茨曼科学研究所Moty Heiblum团队研究了干涉实验中任意子的相干聚束和解离。2025年6月25日出版的《自然》杂志发表了这项成果。
量子霍尔效应中分数准粒子的Aharonov-Bohm干涉通常揭示了它们的基本电荷(e*)。最近,研究组对几种“粒子态”的干涉测量实验报告了ΔΦ的通量周期 = 中等温度下的(e/e*)Φ0(Φ0为通量量子)。研究组报告了填充因子ν下“粒子-空穴共轭”态的干涉测量 = 2/3,3/5和4/7,揭示了ΔΦ的意外通量周期性 = ν−1Φ0。干涉仪每个量子点接触中分区准粒子的测量散粒噪声法诺因子(F)为F = ν而不是基本电荷F = e*/e。这些观察表明,成束(聚集)的基本准粒子的干涉分别发生在相干对、三重和四重粒子上。
沉积在干涉仪主体中心的小金属栅极(顶栅极)在带电时形成反点(或点),从而在(反)点的周边引入局部准粒子。令人惊讶的是,这种电荷导致了“聚集的准粒子”的解离,从而恢复了由准粒子的基本电荷所设定的传统通量周期。然而,(每个量子点接触的)散粒噪声法诺因子始终保持在F = ν,可能是由于伴随共轭态的中性模式。这两种观测结果——聚束和去聚束(或解离)——是当前理论所没有预料到的。Jain的“粒子态”(在较低温度下)和偶数分数量子霍尔态也可能出现类似的效应。
附:英文原文
Title: Coherent bunching of anyons and dissociation in an interference experiment
Author: Ghosh, Bikash, Labendik, Maria, Umansky, Vladimir, Heiblum, Moty, Mross, David F.
Issue&Volume: 2025-06-25
Abstract: Aharonov–Bohm interference of fractional quasiparticles in the quantum Hall effect generally reveals their elementary charge (e*)1,2,3,4,5,6,7,8,9,10,11,12,13,14,15. Recently, our interferometry experiments with several ‘particle states’ reported flux periods of ΔΦ=(e/e*)Φ0 (with Φ0 the flux quantum) at moderate temperatures16. Here we report interference measurements of ‘particle–hole conjugated’ states at filling factors ν=2/3, 3/5 and 4/7, which revealed unexpected flux periodicities of ΔΦ=ν1Φ0. The measured shot-noise Fano factor (F) of the partitioned quasiparticles in each of the quantum point contacts of the interferometer was F=ν (ref. 17) rather than that of the elementary charge F=e*/e (refs. 18,19). These observations indicate that the interference of bunched (clustered) elementary quasiparticles occurred for coherent pairs, triples and quadruplets, respectively. A small metallic gate (top gate), deposited in the centre of the interferometer bulk, formed an antidot (or a dot) when charged, thus introducing local quasiparticles at the perimeter of the (anti)dot. Surprisingly, such charging led to a dissociation of the ‘bunched quasiparticles’ and, thus, recovered the conventional flux periodicity set by the elementary charge of the quasiparticles. However, the shot-noise Fano factor (of each quantum point contact) consistently remained at F=ν, possibly due to the neutral modes accompanying the conjugated states. The two observations—bunching and debunching (or dissociation)—were not expected by current theories. Similar effects may arise in Jain’s ‘particle states’ (at lower temperatures) and at even denominator fractional quantum Hall states20.
DOI: 10.1038/s41586-025-09143-3
Source: https://www.nature.com/articles/s41586-025-09143-3
Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html