| Project/Area Number |
21540344
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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 II
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| Research Institution | Sophia University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Takao 国際基督教大学, アーツ・サイエンス研究科, 研究員 (40327862)
NAKAMURA Tota 芝浦工業大学, 工学部, 教授 (50280871)
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| Project Period (FY) |
2009 – 2011
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| Project Status |
Completed (Fiscal Year 2011)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2011: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2010: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2009: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
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| Keywords | ボースグラス / NMR / μSR / 量子スピン系 / 量子スピン / スピンギャップ / 不純物誘起磁気転移 |
|---|
| Research Abstract |
(CH_3)_2CHNH_3Cu(Cl_xBr_<1-x>)_3 abbreviated IPACu(Cl_xBr_<1-x>)_3 is a mixed system of spin-gap compounds IPACuCl_3 and IPACuBr_3. This mixed system is reported by macroscopic measurements to show a magnetic order when the value of x is between the quantum critical points(QCPs) 0.44 and 0.87. We have investigated microscopically the ground state of the samples x=0.40, 0.45 and 0.50 which are located near the QCP of xc=0.44, by Muon Spin Relaxation(μSR) and NMR measurements. For x=0.40, mSR measurements in zero and longitudinal fields have shown that the spin fluctuation shows a significant slowing down with decreasing temperature, although the magnetic order does not appear down to T=15 mK, indicating that the ground state is an exotic one rather than a gapped one. For x=0.45 and 0.50, mSR and NMR measurements do not show any magnetic order at low temperatures, indicating that the QCP is larger than the reported value of x_c=0.44.
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