近日，美国哥伦比亚大学Raquel Queiroz团队报道了二维金属连续体中的电子束缚态。该研究于2026年10月22日发表在《科学》杂志上。

连续谱中的束缚态（BICs）是一类量子态，尽管位于扩展、离域态的连续谱之内，却仍保持局域化。虽然光学BIC已在光子系统中实现，但在金属背景中实现电子束缚态仍是一项持续存在的挑战。

研究组利用扫描隧道显微镜识别出两个缺陷诱导的电子态，它们在二维范德华金属Pd5AlI2的金属连续谱中保持局域化。计算表明，Pd5AlI2装饰棋盘格晶格上的电子跃迁干涉产生了一个（准）平带，该平带由与色散连续谱正交的空间局域本征态构成。这种受挫晶格中的原子缺陷将相关的平带局域态移入金属连续谱，形成稳健的、对称性保护的BIC。

附：英文原文

Title: Electronic bound states in the continuum in a two-dimensional metal

Author: Morgan Thinel, Xiong Huang, Daniel G. Chica, Simon Turkel, Sebastian E. Rossi, Christie S. Koay, Hong Li, Willa Mihalyi-Koch, Bipasa Samanta, Madisen Holbrook, Aravind Devarakonda, Luca M. Nashabeh, Alexandru B. Georgescu, Xavier Roy, Xiaoyang Zhu, Abhay N. Pasupathy, Raquel Queiroz

Issue&Volume: 2026-10-22

Abstract: Bound states in the continuum (BICs) are quantum states that remain localized despite lying within a continuum of extended, delocalized states. Whereas optical BICs have been realized in photonic systems, achieving electronic bound states embedded in a metallic background remains an ongoing challenge. In this study, we used scanning tunneling microscopy to identify two defect-induced electronic states that remain localized within the metallic continuum of Pd5AlI2, a two-dimensional van der Waals metal. Our calculations suggest that electron-hopping interference on the decorated checkerboard lattice of Pd5AlI2 gives rise to a (quasi) flat band built from spatially localized eigenstates that are orthogonal to the dispersive continuum. Atomic defects within this frustrated lattice shift the associated flat-band localized states into the metallic continuum, forming robust, symmetry-protected BICs.

DOI: 10.1126/science.adt9825

Source: https://www.science.org/doi/10.1126/science.adt9825