| Project/Area Number |
17K18749
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics and related fields
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2017-06-30 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2017: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
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| Keywords | 光電子分光 / 仕事関数 / レーザー / 表面非線形効果 / 光電効果 / 表面光物性 / 非線形光学 / 表面非線形光学 |
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| Outline of Final Research Achievements |
The advances in the laser and angle-resolved photoemission spectroscopy (ARPES) techniques have enabled us to investigate the low-photon-energy photoelectron emission phenomena in depth. Here, we implemented the platform for low-photon-energy ARPES, and demonstrated a new method to measure the work function at the unprecedented precision. (1) We open-accessed a software to map the photoelectron distribution to the Bloch-electron distribution. The software is compatible to the data recorded with“slit-less” analyzers. (2) We developed a compact and versatile 6-eV fiber-laser source. The foot print is 50x56cm2 and operates stably for > 3 months in an ordinary laboratory environment. (3) We found a new method to measure the work function at the unprecedented precision of 1 meV. By using the compact source, we found a phenomenon that the slow end of the photoelectron distribution depends on the emission angle of photoelectrons, which can be utilized for the high-precision measurement.
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| Academic Significance and Societal Importance of the Research Achievements |
仕事関数は固体内から電子を一つ取り出すための最小のエネルギーがである。1905年にアインシュタインは「光子のエネルギーが仕事関数を超えると固体から光電子が放出する」と提唱した。この理論によれば最も遅い光電子が存在するはずである。ところが遅い光電子を精度よく捉えることが技術的に難しかったため、その素性はよくわかっていなかった。本研究ではレーザーと光電子分光の技術の高度化を図り、最も遅い光電子の放出角依存性を捉えることに世界で初めて成功した。その結果、最も遅い光電子は表面垂直方向にの
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