Project/Area Number |
23540387
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Condensed matter physics II
|
Research Institution | The University of Tokyo |
Principal Investigator |
AOKI Masaru 東京大学, 総合文化研究科, 助教 (50302823)
|
Co-Investigator(Renkei-kenkyūsha) |
MASUDA Shigeru 東京大学, 大学院・総合文化研究科, 教授 (50173745)
|
Project Period (FY) |
2011 – 2013
|
Project Status |
Completed (Fiscal Year 2013)
|
Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2012: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2011: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
|
Keywords | 準安定原子 / 電子分光 / 表面磁性 / 準安定励起原子 / スピン偏極 |
Research Abstract |
Electronic properties of potassium-doped dibenzopentacene thin films were studied by electron spectroscopy method using herium metastable atom as a probe. The spectra for KxDBP (0 < x < 3.5) films show three types of gap state in the HOMO-LUMO gap of pristine DBP. The threshold of electron emission for K1DBP is located ~0.1 eV below the Fermi level with no metallic feature, suggesting that K1DBP is a Mott-Hubbard insulator. At the formation of K2DBP, the film has a wide-gap insulator. Upon further deposition of K, the new gap state appears near Fermi level and is attributed to partial electron filling in the LUMO+1~LUMO+3 states, however, the leading edge of the gap state is located ~0.1 eV below Fermi level without a metallic feature. Therefore, the heavily doped species transfers to a Mott-Hubbard insulator again. The gap state plays a key role in superconductivity of K3.5DBP at low temperature.
|