近日，美国普林斯顿大学B. Andrei Bernevig团队报道了过渡金属二硫族化合物中原子带阻滞的观测。这一研究成果发表在2026年3月31日出版的《自然—物理学》杂志上。
拓扑平凡绝缘体主要分为两类：无阻塞原子绝缘体和阻塞原子绝缘体。尽管这两种类型都可以用指数局域的万尼尔轨道来描述，但阻塞原子绝缘体的一个决定性特征是：至少有一个轨道的电荷中心位于晶胞内的空位点，而非占据的原子位点。尽管已有大量理论预测，但迄今尚未实现对阻塞原子相明确、定量的实验鉴定。
研究组展示了1H-NbSe2中此类相存在的直接证据。他们发展了一种方法，利用扫描隧道显微镜探测的局域谱函数，并结合从第一性原理计算获得的轨道波函数，来提取轨道间关联函数。将该技术应用于实空间谱学图像，研究组确定了1H-NbSe2中穿过费米能级的原子能带的轨道间关联函数。结果表明，该能带实现了一个最优紧凑的阻塞原子相。该方法可广泛应用于其他材料平台（包括相关化合物，如同样具有阻塞原子能带的1H-NbSe2），并为探索其他电子相提供了有力工具。
附：英文原文
Title: Observation of an obstructed atomic band in a transition metal dichalcogenide
Author: Clugru, Dumitru, Jiang, Yi, Guo, Haojie, Sajan, Sandra, Wang, Yongsong, Hu, Haoyu, Yu, Jiabin, Bernevig, B. Andrei, de Juan, Fernando, Ugeda, Miguel M.
Issue&Volume: 2026-03-31
Abstract: Topologically trivial insulators are classified into two primary categories: unobstructed and obstructed atomic insulators. Although both types can be described by exponentially localized Wannier orbitals, a defining feature of obstructed atomic insulators is that that the centre of charge of at least one of these orbitals is positioned at an empty site within the unit cell, rather than on an occupied atomic site. Despite extensive theoretical predictions, the unambiguous quantitative experimental identification of an obstructed atomic phase has not yet been achieved. Here we present direct evidence of such a phase in 1H-NbSe2. We develop a method to extract the interorbital correlation functions from the local spectral function probed by scanning tunnelling microscopy and using the orbital wavefunctions obtained from ab initio calculations. Applying this technique to real-space spectroscopic images, we determine the interorbital correlation functions for the atomic band of 1H-NbSe2 that crosses the Fermi level. Our results show that this band realizes an optimally compact obstructed atomic phase. This approach is broadly applicable to other material platforms (including related compounds such as 1H-TaSe2 that also feature obstructed atomic bands) and offers a powerful tool for exploring other electronic phases.
DOI: 10.1038/s41567-026-03196-5
Source: https://www.nature.com/articles/s41567-026-03196-5