Project/Area Number |
09440136
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
固体物性Ⅱ(磁性・金属・低温)
|
Research Institution | KYOTO UNIVERSITY |
Principal Investigator |
MAENO Yoshiteru Graduate School of Science, Kyoto University Associate Professor, 大学院・理学研究科, 助教授 (80181600)
|
Co-Investigator(Kenkyū-buntansha) |
YAMADA Kosaku Graduate School of Science, Kyoto University Professor, 大学院・理学研究科, 教授 (90013515)
ISHIDA Kenji Osaka Univ. Physical Science Research Associate, 基礎工学部, 助手 (90243196)
|
Project Period (FY) |
1997 – 1999
|
Project Status |
Completed (Fiscal Year 1999)
|
Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1998: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 1997: ¥7,200,000 (Direct Cost: ¥7,200,000)
|
Keywords | superconductivity / ruthenate / spin triplet superconductivity / SrィイD22ィエD2RuOィイD24ィエD2 / specific heat / NMR / p-wave supcrconductivity / anisotropic superconductivity / P波超伝導 / 異方的超伝導 / 層状酸化物超伝導 / アイソトープ効果 |
Research Abstract |
The objective of research project is to clarify the superconducting symmetry of SrィイD22ィエD2RuOィイD24ィエD2 mainly through investigation of the specific heat and nuclear magnetic resonance. Through this research project, the quality of the single crystals of SrィイD22ィエD2RuOィイD24ィエD2 has reached an ideal level for most of the investigations. 1. As a major achievement of this project, we have demonstrated by nuclear magnetic resonance that superconductivity of SrィイD22ィエD2RuOィイD24ィエD2 is spin triplet. 2. We have also provided our crystals to many collaborators, who reported a number of important results. In particular, the observation of spontaneous internal field in the superconducting state by muon spin relaxation indicated that the time-reversal-symmetry is spontaneously broken in the superconducting state, another crucial characteristics of the spin-triplet state specific to SrィイD22ィエD2RuOィイD24ィエD2. 3. In addition, we have succeeded in inducing superconducting multiple phases under magnetic fields, characteristic of spin-triplet supcrconductivity. 4. Furthermore, we found that the superconducting transition temperature enhances by a factor of two to 3 K in a eutectic mixture of SrィイD22ィエD2RuOィイD24ィエD2 and Ru metal. 5. At the same time, detailed theoretical models have been developed in order to describe both the superconducting symmetry and the pairing mechanism of SrィイD22ィエD2RuOィイD24ィエD2.
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