Development and investigation of a ferromagnetic topological crystalline insulator with focusing on space inversion symmetry

2016 Fiscal Year Final Research Report

• Project/Area Number: 26870086
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Akiyama Ryota 東京大学, 大学院理学系研究科(理学部), 助教 (40633962)
• Research Collaborator: KURODA Shinji ; FUJISAWA Kazuki ; YAMAGUCHI Tomonari ; SAKURAI Ryutaro ; ISHIKAWA Ryo ; ITO Hiroshi ; NAKANISHI Ryosuke ; Fan Di ; HASEGAWA Shuji ; KIMURA Akio ; SATO Hitoshi
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: トポロジカル絶縁体 / トポロジカル結晶絶縁体 / スピン軌道相互作用 / 2次元伝導 / メゾスコピック / 光電子分光 / 磁性

Outline of Final Research Achievements

In this study, the aim is to investigate the relation between the crystal mirror symmetry and its topological surface state (TSS) in the topological crystalline insulators (TCIs) with doping the magnetic atoms. At first, we optimized the growth conditions of the high-quality single crystal thin films, and observed the weak antilocalization (WAL) effect, which was confirmed to be induced by the TSS. We successfully decrease the bulk carrier density by doping the compensation atom, Sb. The thin film becomes even n-type whereas the non-doped one shows p-type due to many Sn vacancies. Furthermore, the ARPES measurement revealed the Dirac cone derived from the TSS. Lastly with doping of Mn we made the ferromagnetic TCI. The WAL was also observed at the low- Mn-density sample. Thus , we demonstrated the coexistence of the ferromagnetism and the TSS. This means that the TSS can survive under the ferromagnetic interaction if such interaction is not so strong.

Free Research Field

表面物理学、スピントロニクス、磁性、薄膜