美国普林斯顿大学Ali Yazdani团队研究了分数量子霍尔态的高分辨率隧穿光谱。相关论文于2025年3月20日发表在《自然—物理学》杂志上。

在高磁场存在下，二维系统中电子之间的强相互作用产生分数量子霍尔态，该态包含具有分数电荷和分数交换统计的准粒子。研究组展示了超清洁Bernal堆叠双层石墨烯器件中分数量子霍尔态的高分辨率扫描隧道显微镜和光谱学。光谱测量显示，当电子分数化成准粒子的束缚态时，预计会出现剧烈的激发。

研究组发现候选非阿贝尔分数态的能隙比其他相关系统（例如半导体异质结构）中的能隙大五倍，这表明双层石墨烯是操纵这些准粒子和创建拓扑量子比特的理想平台。他们还在其非常干净的石墨烯样品中发现了以前未观察到的分数态。

附：英文原文

Title: High-resolution tunnelling spectroscopy of fractional quantum Hall states

Author: Hu, Yuwen, Tsui, Yen-Chen, He, Minhao, Kamber, Umut, Wang, Taige, Mohammadi, Amir S., Watanabe, Kenji, Taniguchi, Takashi, Papi, Zlatko, Zaletel, Michael P., Yazdani, Ali

Issue&Volume: 2025-03-20

Abstract: Strong interactions between electrons in two-dimensional systems in the presence of a high magnetic field give rise to fractional quantum Hall states that host quasiparticles with a fractional charge and fractional exchange statistics. Here we demonstrate high-resolution scanning tunnelling microscopy and spectroscopy of fractional quantum Hall states in ultra-clean Bernal-stacked bilayer graphene devices. Spectroscopy measurements show sharp excitations that have been predicted to emerge when electrons fractionalize into bound states of quasiparticles. We found energy gaps for candidate non-abelian fractional states that are larger by a factor of five than those in other related systems, for example, semiconductor heterostructures, and this suggests that bilayer graphene is an ideal platform for manipulating these quasiparticles and for creating topological quantum bits. We also found previously unobserved fractional states in our very clean graphene samples.

DOI: 10.1038/s41567-025-02830-y

Source: https://www.nature.com/articles/s41567-025-02830-y