对称破缺陈氏绝缘体及其量子熔化的可视化
近日,美国普林斯顿大学Ali Yazdani团队报道了对称破缺陈氏绝缘体及其量子熔化的可视化。2026年10月22日,《科学》杂志发表了这一成果。
在磁场存在下,莫尔量子材料的电子态会形成霍夫施塔特谱,这为研究能带拓扑与强电子-电子相互作用之间的相互影响提供了一个独特的环境。利用扫描隧道显微镜,研究组分析了与六方氮化硼对齐的双层石墨烯中的霍夫施塔特态,并直接可视化了相互作用驱动的对称性破缺陈绝缘体的形成。
该测量揭示了在霍夫施塔特能带的分数填充下,莫尔单胞发生二倍、三倍或四倍化形成的相,以及具有复杂单胞内波函数的状态。研究组在不同的陈态中可视化了两种不同的量子现象,包括由拓扑缺陷的出现和增殖驱动的量子熔化,以及与相竞争和相分离同时发生的量子转变。
附:英文原文
Title: Visualizing symmetry-broken Chern insulators and their quantum melting
Author: Minhao He, Yen-Chen Tsui, Ran Peng, Kenji Watanabe, Takashi Taniguchi, Oskar Vafek, Ali Yazdani
Issue&Volume: 2026-10-22
Abstract: In the presence of a magnetic field, electronic states of moiré quantum materials develop a Hofstadter spectrum that provides a distinctive setting for studying the interplay between band topology and strong electron-electron interaction. Using scanning tunneling microscopy, we studied Hofstadter’s states in bilayer graphene aligned with hexagonal boron nitride and directly visualized the formation of interaction-driven symmetry breaking Chern insulators. Our measurements revealed the formation of phases that double, triple, or quadruple the moiré unit cell at fractional filling of the Hofstadter bands as well as states with complex intra–unit cell wave functions. We visualized two distinct quantum phenomena in different Chern states, including quantum melting driven by the appearance and proliferation of topological defects and a quantum transition co-occurring with phase competition and separation.
DOI: 10.1126/science.aef0940
Source: https://www.science.org/doi/10.1126/science.aef0940


