Ultra-low temperature scanning-tunneling microscopy studies on bottom-up strongly correlated electron systems

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K18696
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 13:Condensed matter physics and related fields
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Hanaguri Tetsuo 国立研究開発法人理化学研究所, 創発物性科学研究センター, チームリーダー (40251326)
• Co-Investigator(Kenkyū-buntansha): 町田 理 国立研究開発法人理化学研究所, 創発物性科学研究センター, 上級研究員 (60570695)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 走査型トンネル顕微鏡 / 分子線エピタキシー / 超伝導 / スピン計測

Outline of Final Research Achievements

Our goal was to create artificial systems with emergent properties by manipulating atoms using a scanning tunneling microscope and utilizing strongly correlated materials as substrates. Using molecular beam epitaxy, we prepared monolayer 1T-TaSe2, a prototypical Mott insulator, and superconducting monolayer 1H-NbSe2 on graphene. We discovered that the superconducting monolayer 1H-NbSe2 stuck on graphene with a twist, and that the superconducting gap can be controlled through the twist angle. Additionally, we performed atom manipulation to modify a superconducting scanning tip by a magnetic atom and used it as a spin probe with unprecedented energy and spin resolutions.

Free Research Field

物性実験

Academic Significance and Societal Importance of the Research Achievements

当初の目的であった、多数の原子を基板上に配置し、創発物性を探る研究までは期間内に到達できなかったが、基板材料の研究において、積層膜における捻じれ角による超伝導制御という興味深い成果を得た。様々な原子層物質にこの手法を適用することで、超伝導ツイストロニクスと呼ぶべき新しい展開が拓ける。また、原子操作の過程で実現した超伝導探針の磁性元素修飾は、100%のスピン偏極率と数10μeVのエネルギー分解能を持つスピン偏極走査型分光を可能にし、様々な応用が期待できる。