| Project/Area Number |
14350001
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
MUTO Shunichi HOKKAIDO Univ., Grad.School of Eng., Prof., 大学院・工学研究科, 教授 (00114900)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAMINE Kenichi HOKKAIDO Univ., Grad.School of Eng., Instructor, 大学院・工学研究科, 助手 (10241358)
TODA Yasunori HOKKAIDO Univ., Grad.School of Eng., Asso.Prof., 大学院・工学研究科, 助教授 (00313106)
ADACHI Satoru HOKKAIDO Univ., Grad.School of Eng., Asso.Prof., 大学院・工学研究科, 助教授 (10221722)
TAKEUCHI Atsushi Waseda Univ., Sci.and Eng., Prof., 理工学部, 教授 (80298140)
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| Project Period (FY) |
2002 – 2003
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| Keywords | coherent controle / electron spins / quantum dots / circular polarized light / relaxation time / exciton / lifetime / relaxation mechanism |
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| Research Abstract |
Self-assembled InAlAs/AlGaAs quantum dots are grown by the Stranski-Krastanow mode of Molecular Beam Epitaxy (MBE). We measured the spin relaxation time of the structure under the non-resonant optical excitation by using 80 fs pulses by the titanium sapphire laser at wavelength of 780 nm. We used the right circular polarized light for the excitation of carrires to obtain fixed electron spins. The luminescence from the quantum dots at 10 K was divided into the right circular and the left circular components and was temporary resolved by the streak-scope. While the lifetime of the exciton was about 1 18 ns, the spin relaxation time determined by the decay of the polarization of luminescence was 1.31 us, which is comparable to the lifetime. The result indicates that the major relaxation mechanisms in the quantum well are not effective in the quantum dots and that the quantum dot is a good material for the coherent control of electron spins.
As the spin-electronisc material for the future generations, wide-gap semiconductors and a polymer was studied with emphasis on the magnetic or spintronic properties.
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