2020 Fiscal Year Annual Research Report
Exploration of the anharmonicity of phonons modes in molecular crystals with temperature-dependent and high-field terahertz spectroscopy and ab initio simulation
| Project/Area Number |
18K05034
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| Research Institution | Kobe University |
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Principal Investigator |
張 峰 神戸大学, 分子フォトサイエンス研究センター, 助手 (10773046)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | terahertz spectroscpy / quasiharmonicity / thermal expansion / pure anharmonicity / IR intensity / intermolecular vibration / intramolecular vibration |
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| Outline of Annual Research Achievements |
We have performed the quasiharmonic (QH) calculations for the posposal molecular crystals. The QH model induces consistently red shifts of THz peaks with the increase of unit-cell size. We thus deduce that the observed anormalous temperature dependencies of the THz peaks in L-xylose and lactose monohydrate should originate from the pure anharmonicity. Using air-plasma-generation and air-biased-coherent-detection, we have increaed the power of THz radiation by a couple of times compared the regular photo-conductive antenna setup.We have quantitatively analyzed the origins of IR intensities of THz peaks and revealed the important roles played by the marginal intramolecular vibrational components.
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