2023-01-18 ヘルマン･フォン･ヘルムホルツ協会(HGF)
Coherent Correlation Imaging（CCI）と呼ばれるこの技術は、X線を使用して材料のフラクチュエーションを捕捉する。
従来の高解像度X線顕微鏡や電子顕微鏡では、ナノメートルスケールでの速いフラクチュエーションの捕捉は難しい。
CCIは、アルゴリズムを使用して暗い画像からパターンを検出し、それらを組み合わせることで鮮明な画像を生成する。
CCIは、研究者たちに新しい情報を提供する。研究チームは、薄い磁性層でCCIをデモンストレーションし、結果は「Nature」誌に掲載された。
＜関連情報＞
- https://www.helmholtz-berlin.de/pubbin/news_seite?nid=24488&sprache=en&seitenid=1
- https://www.nature.com/articles/s41586-022-05537-9
コヒーレント相関イメージングによる物質のゆらぎ状態の解明 Coherent correlation imaging for resolving fluctuating states of matter
Christopher Klose,Felix Büttner,Wen Hu,Claudio Mazzoli,Kai Litzius,Riccardo Battistelli,Ivan Lemesh,Jason M. Bartell,Mantao Huang,Christian M. Günther,Michael Schneider,Andi Barbour,Stuart B. Wilkins,Geoffrey S. D. Beach,Stefan Eisebitt & Bastian Pfau
Nature Published:18 January 2023
DOI:https://doi.org/10.1038/s41586-022-05537-9
Abstract
Fluctuations and stochastic transitions are ubiquitous in nanometre-scale systems, especially in the presence of disorder. However, their direct observation has so far been impeded by a seemingly fundamental, signal-limited compromise between spatial and temporal resolution. Here we develop coherent correlation imaging (CCI) to overcome this dilemma. Our method begins by classifying recorded camera frames in Fourier space. Contrast and spatial resolution emerge by averaging selectively over same-state frames. Temporal resolution down to the acquisition time of a single frame arises independently from an exceptionally low misclassification rate, which we achieve by combining a correlation-based similarity metric1,2 with a modified, iterative hierarchical clustering algorithm3,4. We apply CCI to study previously inaccessible magnetic fluctuations in a highly degenerate magnetic stripe domain state with nanometre-scale resolution. We uncover an intricate network of transitions between more than 30 discrete states. Our spatiotemporal data enable us to reconstruct the pinning energy landscape and to thereby explain the dynamics observed on a microscopic level. CCI massively expands the potential of emerging high-coherence X-ray sources and paves the way for addressing large fundamental questions such as the contribution of pinning5,6,7,8 and topology9,10,11,12 in phase transitions and the role of spin and charge order fluctuations in high-temperature superconductivity13,14.
