哥伦比亚大学《Science》研究：金属 Pd5AlI2 中电子波首次被量子干涉困住
哥伦比亚大学研究团队在《Science》发表研究称，电子波首次在一种名为 Pd5AlI2 的金属中被困住。理论物理学家 Raquel Queiroz 表示，量子力学预言电子波理论上即使有无限多条逃逸路径也可被困住，这一效应此前已在光波中见到，但从未在电子中观察到。
Pd5AlI2 由哥伦比亚大学 Xavier Roy 化学实验室数年前制得，可剥离成二维层并保持金属特性。研究团队与实验物理学家 Cory Dean、Aravind Devarakonda 等合作，此前在《Nature Physics》发表该材料受挫电子跳跃的结果；物理学家 Abhay Pasupathy 实验室以原子尺度扫描与光谱仪器成像时，在晶体晶格原子缺陷附近发现被束缚的电子波图案。
研究团队称，这是连续谱束缚态（BIC）在金属中的首次清晰证据。团队表示，目前电子 BIC 由材料生长中的缺陷随机产生，Roy 与 Pasupathy 正在探索在特定位置有意引入缺陷的方法，以调控干涉图案；研究团队称还应存在其他具有类似受挫晶格结构的金属类别可承载电子 BIC。
Columbia Study in Science: Electron Waves Trapped for the First Time in Metal Pd5AlI2 by Quantum Interference
A team of Columbia University researchers reported in Science that waves of electrons became trapped for the first time in a metal called Pd5AlI2. Theoretical physicist Raquel Queiroz said quantum mechanics predicts that an electron wave can theoretically remain trapped even when there are infinitely many paths for it to escape, an effect known from light waves but never before seen for electrons.
Pd5AlI2 was made a few years ago in Xavier Roy's chemistry lab at Columbia and can be peeled into two-dimensional layers while retaining its metallic characteristics. Working with experimental physicists Cory Dean and Aravind Devarakonda, the team had published results on frustrated electron hopping in the material in Nature Physics last year. Physicist Abhay Pasupathy's lab, using scanning and spectroscopy instruments that image materials with atom-scale accuracy, noticed unexpected patterns that turned out to be electron waves bound in place near atomic defects in the crystal lattice.
The team said the observation is the first clear evidence of a bound state in the continuum, or BIC, in a metal. Electronic BICs are currently random, resulting from defects arising during the growth of Pd5AlI2 in the lab, and Roy and Pasupathy are exploring ways to deliberately introduce defects into specific places in the metal to fine-tune the resulting interference patterns. The team said other classes of metals with similar frustrated lattice structures should also be able to host electronic BICs.
来源：哥伦比亚大学
发布：GSM·美国（发布链接）
图片来源：图中是一台扫描隧道显微镜的结构，该类仪器可对材料作原子尺度成像，本研究团队用扫描与光谱仪器观察到被束缚的电子波。来源：Wikimedia Commons, File:Scanning Tunneling Microscope Structure (5941082310).jpg, National Institute of Standards and Technology, Public domain。
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