Fine electronic states of Dirac-electron systems studied by high-resolution ARPES

2016 Fiscal Year Final Research Report

• Project/Area Number: 25287079
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: Sato Takafumi 東北大学, 理学(系)研究科(研究院), 准教授 (10361065)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: トポロジカル絶縁体 / 鉄系超伝導体 / ディラックコーン / スピン偏極 / フェルミ面

Outline of Final Research Achievements

We have developed high-resolution spin-resolved photoemission spectrometer to clarify the relationship between basic electronic states and origin of anomalous physical properties in Dirac electron systems, and have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) studies on graphene-based materials, iron-based superconductors, and topological insulators/semimetals. We have succeeded in (i) controlling the band gap of graphene by surface adsorption, (ii) observing Dirac-cone band in the nematic phase of parent iron-based superconductors, (iii) controlling Dirac-fermion mass at the interface between ultrathin ferromagnet and Rashba metal, and (iv) discovering new types of topological semimetals. From these results, we have clarified close relationship among Dirac-cone electronic states, crystal symmetry, and origin of unconventional physical properties.

Free Research Field

光電子固体物性