近日，美国普林斯顿大学Ali Yazdani团队报道了可视化相互作用驱动的量子霍尔边缘态重构。该项研究成果发表在2025年12月17日出版的《自然》杂志上。

众多拓扑物相中存在无能隙边界态，这些边界态的性质可显著受电子相互作用影响。即便是研究历史最悠久的量子霍尔边界态——形成于二维电子系统边界——其相互作用导致的改变本质仍难以捉摸。尽管局部探测技术已取得进展，关键实验挑战依然存在：缺乏微观尺度上边界态内部结构的直接信息，以及边缘无序性带来的干扰。

研究组利用扫描隧道显微镜，对石墨烯中静电定义的原始量子霍尔边缘态进行高空间分辨率成像，揭示了关联效应如何在磁学尺度与原子尺度上共同决定边缘通道的结构特征。对于零级朗道能级中的整数量子霍尔态，他们发现：相互作用会重整化边缘态速度，决定共传播模式的空间分布，并诱导出与体态不同的、出乎意料的自发边缘谷极化现象。虽然部分观测结果可用平均场理论解释，但另一些现象却揭示了该理论的局限性，凸显了边缘涨落与通道间耦合的关键作用。

研究还进一步拓展至对分数量子霍尔相边缘态的空间分辨测量，并在这类手性Luttinger液体中探测到相互作用的谱学特征。该工作确立了扫描隧道显微镜作为探索二维拓扑物相边缘物理的强大工具，该领域正快速扩展，涵盖近期实现的分数量子陈绝缘体等新颖物态。

附：英文原文

Title: Visualizing interaction-driven restructuring of quantum Hall edge states

Author: Yu, Jiachen, Han, Haotan, Wolinski, Kristina G., Fan, Ruihua, Mohammadi, Amir S., Wang, Tianle, Wang, Taige, Cohen, Liam, Watanabe, Kenji, Taniguchi, Takashi, Young, Andrea F., Zaletel, Michael P., Yazdani, Ali

Issue&Volume: 2025-12-17

Abstract: Many topological phases host gapless boundary modes that can be markedly modified by electronic interactions. Even for the long-studied edge modes of quantum Hall phases1,2, forming at the boundaries of two-dimensional electron systems, the nature of such interaction-induced changes has been elusive. Despite advances made using local probes3,4,5,6,7,8,9,10,11,12,13, key experimental challenges persist: the lack of direct information about the internal structure of edge states on microscopic scales, and complications from edge disorder. Here we use scanning tunnelling microscopy to image pristine electrostatically defined quantum Hall edge states in graphene with high spatial resolution and demonstrate how correlations dictate the structures of edge channels on both magnetic and atomic length scales. For integer quantum Hall states in the zeroth Landau level, we show that interactions renormalize the edge velocity, dictate the spatial profile for co-propagating modes and induce unexpected edge valley polarization, which differs from the bulk. Although some of our findings can be understood by mean-field theory, others show breakdown of this picture, highlighting the roles of edge fluctuations and inter-channel couplings. We also extend our measurements to spatially resolve the edge state of fractional quantum Hall phases and detect spectroscopic signatures of interactions in this chiral Luttinger liquid. Our study establishes scanning tunnelling microscopy as a promising tool for exploring the edge physics of the rapidly expanding group of two-dimensional topological phases, including recently realized fractional Chern insulators.

DOI: 10.1038/s41586-025-09858-3

Source: https://www.nature.com/articles/s41586-025-09858-3