| Project/Area Number |
15K05132
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Condensed matter physics I
|
|---|
| Research Institution | Hiroshima University |
|---|
Principal Investigator |
Arita Masashi 広島大学, 技術センター, 技術専門職員 (20379910)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
伊賀 文俊 茨城大学, 理学部, 教授 (60192473)
|
|---|
| Co-Investigator(Renkei-kenkyūsha) |
Shimada Kenya 広島大学, 放射光科学研究センター, 教授 (10284225)
|
|---|
| Project Period (FY) |
2015-04-01 – 2018-03-31
|
| Project Status |
Completed (Fiscal Year 2017)
|
| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
|
|---|
| Keywords | トポロジカル絶縁体 / 近藤絶縁体 / 角度分解光電子分光 / トポロジカル近藤絶縁体 |
|---|
| Outline of Final Research Achievements |
We have investigated the topological Kondo insulator: SmB6, the candidate material: YbB6, compounds：Sm1-xYbxB6 and Yb1-xTmxB6 by means of angle resolved photoemission spectroscopy. In Yb1-xTmxB6, Dirac-corn-like band structure is observed at X(bar) and Gamma(bar) near EF. According to the band calculation, the structures are derived from bulk bands which have small overlap between valence and conduction bands. Thus, it is assumed that YbB6 is not the topological Kondo insulator.
Since there are no changes of the band structures between SmB6 and Sm0.9Yb0.1B6, the electronic structure of SmB6 are robust for the Yb substitution less than 10 % of the Sm site. In SmB6, we found the metallic band structure which forms the circular Fermi surface centered at Gamma(bar) point at 10 K. Metal insulator transition is clearly observed in the band between 30K and 60 K. It is concluded that the band stems from the topological surface state.
|
