Development of time resolved THz-STM

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H05982
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: University of Tsukuba
• Principal Investigator: Yoshida Shoji 筑波大学, 数理物質系, 准教授 (90447227)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 走査プローブ顕微鏡 / テラヘルツ / 超高速分光 / 表面科学

Outline of Final Research Achievements

In this study, we have developed a novel time-resolved microscopy - THz-STM. We have achieved time-resolved measurement with extremely high signal to noise ratio by using a highly intense and high repetition rate THz pulse, which was generated using high power femtosecond pulse laser.
We have applied the technique to probe the ultrafast dynamics of various materials. For example, we have succeeded in measuring ultrafast carrier relaxation and ultrafast metal-insulator transition in two dimensional layered materials, and we have captured electron motion in an organic semiconductor. We have demonstrated sub-ps time resolution and atomic spatial resolution of the method from the above results.

Free Research Field

走査プローブ顕微鏡

Academic Significance and Societal Importance of the Research Achievements

本研究で開発した時間分解THz-STMを用いて、超高速領域での光励起キャリアダイナミクスや電子状態の変化を原子レベルで捉えることに成功した。サブps時間分解能、原子分解能を両立した時間分解計測による表面ダイナミクスのイメージングが可能となり、今後様々な試料の光応答・ダイナミクスを原子・分子のスケールで解明できるようになると期待される。