Construction of new methodology of studying the structure of superconducting gap of multigapped superconductors using Leggt mode etc

2016 Fiscal Year Final Research Report

• Project/Area Number: 26610094
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: MAEDA Atsutaka 東京大学, 大学院総合文化研究科, 教授 (70183605)
• Co-Investigator(Renkei-kenkyūsha): IMAI Yoshinori 東北大学, 大学院理学研究科, 講師 (30435599) ; HU Xiao 独立行政法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点・ナノ物性理論ユニット, ユニット長 (90238428) ; TAJIMA Setsuko 大阪大学, 理学(系)研究科(研究院), 教授 (70188241)
• Research Collaborator: NABESHIMA Fuyuki 東京大学, 大学院総合文化研究科, 助教 (30782776) ; OKADA Tatsunori 東北大学, 金属材料研究所, 助教 (50793775)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 鉄カルコゲナイド / パルスレーザー蒸着 / 多ギャップ超伝導 / 相分離 / 磁束フロー / レゲットモード / 時間領域THz分光 / 渦の解離

Outline of Final Research Achievements

Using Pulsed Laser Deposition technique, we succeeded in synthesizing a series of epitaxial films of FeSe(1-x)Tex including the composition range where bulk crystals are not available because of the phase separation. We also succeeded in increasing Tc among these series of film samples. Utilizing the merit of our series of samples, we have performed the investigation of various physical properties, part of which is in collaborations with other research groups, as a function of Te content, x. Among the results, we obtained signals, probably corresponding to the Leggett mode, details of which are now under investigation. We also propose several new aspects of multigapped superconductors theoretically. As for the flux flow, we did not find any signature of the dissociation of the components of multiple gapped superconductivity, which is in agreement with the latest theoretical prediction.

Free Research Field

固体物理学