Novel dynamics of quantum condensate investigated by local micorwave complex conductivity measurement

2014 Fiscal Year Final Research Report

• Project/Area Number: 23244070
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: MAEDA Atsutaka 東京大学, 総合文化研究科, 教授 (70183605)
• Co-Investigator(Kenkyū-buntansha): KATO Yusuke 東京大学, 大学院総合文化研究科, 教授 (20261547)
• Co-Investigator(Renkei-kenkyūsha): IMAI Yoshinori 東京大学, 大学院総合文化研究科, 助教 (30435599) ; HANAGURI Tetsuo 独立行政法人理化学研究所, 創発物性科研究センター, チームリーダー (40251326) ; KONDO Ryusuke 岡山大学, 大学院自然科学研究科, 准教授 (60302824) ; FUKATSU Susumu 東京大学, 大学院総合文化研究科, 教授 (60199164) ; YASUTAKE Yusuke 東京大学, 大学院総合文化研究科, 助教 (10526726)
• Research Collaborator: TAKAHASHI Hideyuki 東京大学, 大学院総合文化研究科
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: マイクロ波 / マイクロ波顕微鏡 / STM / 鉄系超伝導体 / 電気伝導度分布 / 局所電気伝導度 / 銅酸化物超伝導体 / トポロジカル絶縁体

Outline of Final Research Achievements

It is important for modern scanning microwave microscope to overcome an influence of the surface roughness. Here we report microwave imaging of phase-separated iron chalcogenide KxFeySe2 (x = 0.8, y = 1.6 - 2) using scanning tunneling/microwave microscope developed by ourselves, distinguishing electric contrast from topography-induced contrast using STM/SMM. We successfully observed the characteristic modulation of local electric property originating from mesoscopic phase separation of the metallic and the semiconducting phase in two different scanning modes; constant current mode and constant Q mode. In particular, the constant Q scanning is turned to be extremely useful because we can get an qualitative image in which topographic contrast is largely eliminated without degradation of the spatial resolution. This technique, with a further improvement, should introduce novel aspect for condensed matter physics reseraches.

Free Research Field

物性物理学