| Project/Area Number |
15540309
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Osaka University |
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Principal Investigator |
FUJII Kenichi Osaka University, Graduate School of Science, Associate Professor, 大学院・理学研究科, 助教授 (10189988)
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| Co-Investigator(Kenkyū-buntansha) |
NAKATA Hiroyasu Osaka-kyoiku University, Department of Arts and Science, Professor, 教育学部, 教授 (60116069)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Keywords | quantum ring / microwave / cyclotron resonance / spintronics / 局在 / テラヘルツ発振 |
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| Research Abstract |
We fabricated various sire of single quantum ring structures and ring array structures to investigate the electronic states in the quantum ring structures. For the fabrication of the ring structures, e-beam lithography and wet etching techniques was employed to GaAs/AlGaAs heterostructures. In the fabricated single ring structures being as small as possible, Aharonov-Bohm oscillation could be observed in the magnetoresistance measurements at 4.2 K Furthermore, under irradiation of microwaves, we found a new broad peak of resistance at the magnetic field at which the cyclotron radius equals to the geometrically defined radius of the ring. The appearance of the broad peak in several ring structures with different ring size indicates the absorption of the microwaves due to the electrons in the ring structure. The traveling tune of electrons through a ring is much shorter than the period of the applied microwaves. This experimental result suggests that the existence of the localized electrons in the ring at the magnetic field at least for the tune mare than a period of the microwaves. For the increasing of the resistance, the localized electrons have to interact with conducting electrons tough the ring. The observed assistance peak can be explained by the existence of the localized electrons in the quantum ring.
This experimental results apply to the crew type of anntena and the development of spin transistors which can work at high frequency like microwaves. For the application of the quantum ring to the anntena, we tried to make snail solid state light emitter with Ge : Te. For the application of the quantum, ring to the spintronics field, we also investigated the electronic states of the another III-V compound heterostructures, InGaAs/InAlAs and InGaSb/InAlSb heterostructures. In this stage, we concluded that InGaAs/InAlAs heterostructures is suitable for making a quantum ring structure for the development of spin transistors
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