光学顕微鏡で結晶内の原子位置を可視化する新技術（Optical microscope helps locate atomic positions in crystals）

2025-10-22 マサチューセッツ工科大学(MIT)

MITの物理学チーム（Yuqin “Sophia” Duan、Dirk Englund教授ら）は、光学顕微鏡を用いて原子レベルの位置特定を可能にする新手法「DIGIT（Discrete Grid Imaging Technique）」を開発した。従来の光学顕微鏡は回折限界により原子を直接識別できなかったが、DIGITは既知の結晶構造を“座席表（seating chart）”として参照し、統計的解析により原子の最も確からしい位置を0.178オングストローム精度で特定する。電子顕微鏡のような高エネルギー環境を必要とせず、生体試料などにも応用可能。量子デバイス設計や半導体・超伝導体中の欠陥解析、さらには生体分子構造の精密可視化に貢献する可能性がある。研究成果は『Nature Communications』に掲載された。

MIT physicists have developed discrete grid imaging technique (DIGIT), an optical super-resolution technique that maps quantum emitters to lattice sites with atomic localization precision (as represented in this artist’s interpretation).
Credit: Courtesy of the researchers

＜関連情報＞

蛍光顕微鏡における原子レベルの正確な局在化に向けたベイズ的アプローチ A Bayesian approach towards atomically-precise localization in fluorescence microscopy

Yuqin Duan,Qiushi Gu,Hanfeng Wang,Yong Hu,Kevin C. Chen,Matthew E. Trusheim & Dirk R. Englund
Nature Communications Published:21 October 2025
DOI:https://doi.org/10.1038/s41467-025-64083-w

Abstract

Super-resolution microscopy has revolutionized the imaging of complex physical and biological systems by surpassing the Abbe diffraction limit. Recent advancements, particularly in single-molecule localization microscopy, have pushed localization below nanometer precision, by applying prior knowledge of correlated fluorescence emission from single emitters. However, achieving a refinement from 1 nm to 1 Ångström demands a hundred-fold increase in collected photon signal. This quadratic resource scaling imposes a fundamental barrier in single-molecule localization microscopy, where the intense photon collection is challenged by photo-bleaching, prolonged integration times, and inherent practical constraints. Here, we break this limit by harnessing the periodic nature of the atomic lattice structure. Applying this discrete grid imaging technique (DIGIT) in a quantum emitter system, we observe an exponential collapse of localization uncertainty once surpassing the host crystal’s atomic lattice constant. We further applied DIGIT to a large-scale quantum emitter array, enabling parallel positioning of each emitter through wide-field imaging. Collectively, these advancements establish DIGIT as a competitive tool for achieving unprecedented, precise measurements, ultimately paving the way to direct optical resolution of crystal and atomic features within quantum and biological systems.