Development of a noise-cancelling STM aimed at fast spectroscopic imaging

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19027
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 29:Applied condensed matter physics and related fields
• Research Institution: National Institute for Materials Science
• Principal Investigator: YOSHIZAWA Shunsuke 国立研究開発法人物質・材料研究機構, 先端材料解析研究拠点, 主任研究員 (60583276)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: 走査トンネル顕微鏡 / 分光イメージング / 多変量解析 / ノイズ除去

Outline of Final Research Achievements

Spectroscopic imaging by scanning tunneling microscopy is almost the only way to visualize the superconducting vortices in real space in high magnetic fields. However, in order to observe non-equilibrium vortices, the time required for a single scan must be reduced, and new methods to remove vibration noise are desired. We proposed a method to extract features from spectroscopic imaging data using independent component analysis, and to separate the signal and the noise according to the presence or absence of spatial correlation.We have also improved the speed of spectroscopic imaging by using multi-pass scanning mode.

Free Research Field

低温物性、表面科学

Academic Significance and Societal Importance of the Research Achievements

独立成分分析を利用する方法は、ノイズ除去だけでなく、走査トンネル顕微鏡で測定された複雑なスペクトルの起源を切り分けて考察する手がかりも提供できる。処理自体は大変簡便であるので、超伝導体以外にも、空間的に不均一な系を含むさまざまな物質で役にたつことが期待される。