2018 Fiscal Year Annual Research Report
Ultrafast dynamics and resonance effects in photoemission from surfaces
| Project/Area Number |
16K05393
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| Research Institution | Chiba University |
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Principal Investigator |
KRUEGER PETER 千葉大学, 大学院工学研究院, 教授 (30706362)
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Keywords | 光物性 / 表面 / 界面 |
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| Outline of Annual Research Achievements |
In this year we have focused on resonant photoemission. First we have developed a method for computing all parameters needed in a ligand field multiplet model from an ab initio DFT calculation [P. Krueger, Radiat. Phys. Chem. (2019) in press]. We obtained very good results for transition metal oxides and metal-organic molecules. This is important because we are using the multiplet model for the atomic part of the resonant photoemission calculation. Then we have extended the multiplet program to include the Auger decay. The program can now calculate angle-resolved resonant photoemission (and Auger) spectra of an atom in a ligand field. We have tested the program for 2p-3d resonant spectra in nickel and obtained good agreement with experiment. We find that the angular intensity distribution depends much on light polarization and binding energy. When circular polarized light is used, the angular momentum of the photon (helicity) is partly transferred to the photoemitted electron, but the effect is smaller than in direct photoemission and it strongly depends on the final state. For nickel, we find that the orbital angular momentum of the emitted electron is parallel to the photon helicity at the dominant spin singlet peak (1G final state), but it is antiparallel for the strongest triplet peak (3F). This explains a recent, surprising experimental observation. Now we are inserting the calculated electronic wave function into a photoelectron diffraction program. From this we shall obtain the full angular pattern of the resonant photoemission, which was the aim of this project.
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