| Project/Area Number |
10206203
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas (B)
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| Allocation Type | Single-year Grants |
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| Research Institution | Kyoto University |
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Principal Investigator |
MOMOSE Takamasa Kyoto University, Chemistry Department, Associate Professor, 理学研究科, 助教授 (10200354)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥23,900,000 (Direct Cost: ¥23,900,000)
Fiscal Year 2000: ¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 1999: ¥8,800,000 (Direct Cost: ¥8,800,000)
Fiscal Year 1998: ¥10,500,000 (Direct Cost: ¥10,500,000)
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| Keywords | quantum solid / solid hydrogen / tunneling reaction / pure dephasing / nuclear spin relaxation / ions / high-resolution spectroscopy / infrared spectroscopy / 化学反応 / レーザー分光 / トンネル / 放射線 / 反応ダイナミックス / 線幅 |
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| Research Abstract |
Solid hydrogen, known as a quantum crystal, shows extremely narrow spectral linewidths, which allow us to study interactions and dynamics of molecules imbedded in the solid by high-resolution spectroscopy. In order to study quantum effects on dynamics of molecules, we have investigated excited states and its relaxation processes, and chemical reactivities of molecules imbedded in solid parahydrogen using high-resolution rotation-vibration spectroscopy. Main results we obtained are as follows.
(1) Relaxation processes of electronic and vibrational excited states in quantum solid.
We found a T^4 temperature dependence of pure dephasing of vibrational excited states of molecules imbedded in the quantum solid. The T^4 temperature dependence is intrinsically different from the T^7 temperature dependence in classical medium. We also found that nuclear spin relaxation in the quantum solid is mainly caused by the intramolecular nuclear spin-rotation interaction and the one-phonon lattice rotation interaction.
(2)Ions in quantum solid.
In order to study ions in quantum solids, we irradiated solid hydrogen by gamma-ray. The irradiated solid showed new complicated spectral features with extremely narrow spectral linewidths. These spectral features are attributed to the transitions of hydrogen molecules induced by electric fields of ions produced in the solid.
(3) Quantum effects on tunneling reaction.
We have investigated X+H_2→XH+H type tunneling reaction in solid hydrogen by infrared spectroscopy. The tunneling reaction rate depends drastically on the zero-point vibration of reactants and products. Moreover, the rate depends significantly on the vibrational quantum number of reactants.
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