Enhancing the superconducting critical temperature by single layer films

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13832
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Naito Michio 東京農工大学, 工学(系)研究科(研究院), 教授 (40155643)
• Co-Investigator(Kenkyū-buntansha): 迫田 將仁 東京農工大学, 工学(系)研究科(研究院), 助教 (80735556)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 鉄系超伝導体 / 単原子層薄膜 / FeSe / 分子線エピタキシー / 電気二重層トランジスタ

Outline of Final Research Achievements

The superconductivity in Fe(Se,Te) was reported just after superconducting FeAs compounds were discovered by the Hosono group in 2008. At the beginning, the Tc of Fe(Se,Te) may not go over 15 K, but it was reported in 2012 by the Chinese groups that the Tc of monolayer FeSe films on SrTiO3 substrates may reach 77 K. Furthermore, very recently (during the period of this Kakenhi research), it was announced by several groups including Japanese groups that Tc as high as 40 K can be reached in FeSe ultrathin films given carrier injection and/or electrochemical etching by an EDLT (Electric Dipole Layer Transistor). Therefore such experiments have also been performed in our research. As a result, we achieved Tc ~ 50 K in FeSe films consisting of several molecular layers on Al2O3 substrates, which demonstrate that a SrTiO3 substrate is not prerequisite to achieve high-Tc in FeSe films.

Free Research Field

超伝導物質科学