| Project/Area Number |
06804016
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
YAMANAKA Akio Hokkaido Univ., Res. Inst. for Elect. Scie., Res. Associ., 電子科学研究所, 助手 (30182570)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | High-Tc superconductor / Electronic Raman scattering / Time-resolved electronic-Ramam scattering / D-wave superconductor / Superconducting quasi-particle / Superconducting gap / Sr_2RuO_4 superconductor / Electron correlation / 超伝導体 / 動的応答特性 / フォノンラマン散乱 / パルスレーザー / インターカレーション化合物 / ハロゲンインターカレーション |
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| Research Abstract |
To consider the mechanism of the high-Tc superconductivity in copper-oxides, dynamical property of the superconducting quasi-particles is a crucial information. this is because a spectrum of the superconducting gap excitation, which provides a key to clarify the symmetry of the order parameter, is strongly affected by a life time of the quasi-particle. The purpose of the project is to study the dynamical property of the quasi-particle and to clarify the magnitude of the superconducting gap and its symmetry.
In this project several technique have been developed. (1) a very simple and effective band-filter has been developed to reduced fluorescence signals come out from a mode-locked dye-laser, which prevent a measurement of the electronic Raman scattering. (2) a new computer software has been developed to remove the cosmic-ray noise which prevents a highly sensitive measurement with using CCD camera. As a result, we open a door to study dynamical property of superconductors by the electronic Raman scattering. The results of the present study are
(1) the pairing state of high-Tc superconductors is d-wave and the order parameter transforms as x^2-y^2.
(2) the electronic state in a recently discovered Sr_2RuO_4 superconductor is affected strongly by an electron correlation effect.
(3) the intercalation of bromine into BiO-planes of Bi_2Sr_2CaCu_2O_8 strikingly increases conducting hole carriers in the CuO_2-plane.
(4) the hybridization between Ti-3d and O-2p states predominates the ferroelectronic instability in ATiO_3 perovskites.
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