1992 Fiscal Year Final Research Report Summary
Dynamical Study of Photoexcited States in Semiconductors by Means of Femtosecond Pump-and-Probe Spectroscopy
| Project/Area Number |
03402007
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | University of Tsukuba |
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Principal Investigator |
MASUMOTO Yasuaki Institute of Physics, University of Tsukuba, Professor, 物理学系, 教授 (60111580)
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| Co-Investigator(Kenkyū-buntansha) |
MISHINA Tomobumi Institute of Physics, University of Tsukuba, Research Associate, 物理学系, 助手 (10209744)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Femtosecond / Pump-and-Probe Spectroscopy / Nonequilibrium Electron Distribution / Exciton / Coherent Phonon / Quantum Beat / Type-II Quantum Well / Excitonic Polariton |
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| Research Abstract |
<Observation of nonequilibrium electrons in CdSe> Femtosecond pump-and-probe spectroscopy was applied to highly excited CdSe. Nonequilibrium distribution of electrons was observed for 50 fs. <Exciton-hole collision in type-II AlGaAs-AlAs quantum wells> Exciton-hole collision rate was measured by means of time-resolved degenerate four-wave mixing. Phase relaxation of excitons is dominated by the collision between the excitons and long-lived holes. <Observation of coherent optical phonons in BiI_3> Resonant coherent lattice vibrations in the vicinity of the indirect absorption edge in a BiI_3 lattice crystal are observed in a femtosecond pump-and-probe experiment. The coherent transverse optical lattice vibration, which has a period of 300 fs, continues for more than 100 cycles. <Quantum beats of Wannier excitons and excitonic polaritons> Quantum beats of Wannier excitons and excitonic polaritons were observed in ZnP_2. Qunatum beat originates from Wannier excitons whose principal quantum numbers n are 2,3 and 4. Polariton quantum beat was also observed as a result of interference of both upper and lower polaritons around the n =1 resonance.
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