ESR Study of a novel elementary excitation : Breather in quantum spin chains
| Project/Area Number |
12640335
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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 |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | OKAYAMA UNIVERSITY (2001)
Tohoku University (2000) |
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Principal Investigator |
NOJIRI Hiroyuki Faculty of Science, Professor, 理学部, 教授 (80189399)
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| Co-Investigator(Kenkyū-buntansha) |
KOYAMA Keiichi Tohoku Univ., Institute for Materials Research, Associate Professor, 金属材料研究所, 助教授 (70302205)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Soliton / High Magnetic Field / Non-linear excitation / Antiferromagnetic chain / ESR / 非線形現象 / 量子相転移 |
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| Research Abstract |
A non-linear excitation : breather has been studied in a quantum antiferromagnetic chain CuBenzoate by means of ESR. The anisotropy and the field dependence of the field induced gap has been investigated by a high resolution ESR. In low field region, the exponent of the gap on the magnetic field found to be very close to theoretical value of 2/3. A dynamical crossover between the gapped soliton-breather regime and the gapless spinon regime has been found as the anomaly of ESR line shape and line width. By using a Voight configuration, the energy of breather mode has been determined very precisely without a correction of Zeeman term. In the high field regime, a decrease of the exponent is found. A coupling constant of a sign-Gordon model has been experimentally obtained from the accurate field dependence of the breather mass. High field zero field muon spin rotation experiments have been performed down to 16 mK and no evidence of a long range order is found. It shows the extremely good one-dimensionality of Cubenzoate. Several different types of higher order breather excitations have also found.
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Report
(3 results)
Research Products
(17 results)
