1998 Fiscal Year Final Research Report Summary
ELECTRONIC STATES OF (GaP)m(AlP)n SHORT PERIOD SUPERLATTICES AND MULTI-QUANTUM WELL STRUCTURES AND THE MECHANISM OF PHOTOLUMINESCENCE
| Project/Area Number |
08454086
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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 |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | SCIENCE UNIVERSITY OF TOKYO |
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Principal Investigator |
KAMIMURA Hiroshi Science University of Tokyo, Graduate School of Science, Institute of Physics, Professor, Dr., 理学部, 教授 (60011475)
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| Co-Investigator(Kenkyū-buntansha) |
SUWA Yuji Hitachi Advance Research Laboratory, Research scientist, 前助手 (20216500)
NAKAYAMA Takashi Chiba University, Department of Physics, Associate Professor, Dr., 理学部, 助教授 (70189075)
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| Project Period (FY) |
1996 – 1998
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| Keywords | first principles / bound exciton / semiconductor superlattices / strong magnetic field / optical properties / copper oxides / many-electreon states / antiferro magnetic order |
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| Research Abstract |
This three-year research project started on April of 1996 and has been conducted successfully. The aim of this project was twofold : One was to elucidate the origin of the unusual behavior of photoluminescence (PL) observed in (GaP)n(AJIP)n short period superlattices, in which the PL intensity decreases with increasing a magnetic field in the strong field regime in the Faraday configuration. In the present research we have clarified that a bound exciton trapped at a pseudo-dot type defect at the interface is responsible for the above unusual behavior. The present result was appreciated in the field of semiconductors and we have given a talk in international conferences. Another aim was to clarify a many-body electronic structures of underdoped cuprates. By using the multi-configuration self-consistent field variational method for a single CuO_5 pyramid embedded in YBCO7 with Tc=90K and then by introducing the transfer interactions between CuO_5 pyramids, unusual electronic states were clarified. That is, the dopant holes move coherently by taking the Zhang-Rice spin singlet and Hund's coupling triplet alternately in the apin correlated region of anti-ferromagnetic ordering due to Cu localized spins, without destroying the anti-ferromagnetic order.
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