Scanning tunneling potentiometry measurements on surface/ultrathin superconductors

2016 Fiscal Year Final Research Report

• Project/Area Number: 16K13683
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Hirahara Toru 東京工業大学, 理学院, 准教授 (30451818)
• Research Collaborator: YOSHINO Ryo ; TANAKA Tomoaki
• Project Period (FY): 2016-04-01 – 2017-03-31
• Keywords: 超伝導 / 超薄膜 / 走査トンネル顕微鏡

Outline of Final Research Achievements

The purpose of the present research is to unveil the origin of the high critical current in surface/ultrathin superconductors using microscopic electrical conductivity measurements. First, we searched for the condition to grow a high-quality one unit-cell (1UC) thick FeSe superconducting film on SrTiO3(001) substrate. We found that a large domain 1UC FeSe can be grown by co-depositing Fe and Se at the substrate temperature of 520 degrees from scanning tunneling microscopy (STM) measurements. Furthermore, we found that the superconducting properties of 1UC FeSe film showed local variations from scanning tunneling spectroscopy (STS) measurements at 5 K. We will clarify how these local properties affect the magnitude of the critical current from scanning tunneling potentiometry (STP) measurements in the near future.

Free Research Field

物性実験(表面・界面)