| Project/Area Number |
24540384
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
TOKUNAGA Masashi 東京大学, 物性研究所, 准教授 (50300885)
TAKAMASU Tadashi 物質・材料研究機構, 量子ドットセンター, グループリーダー (60212015)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2014: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2012: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
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| Keywords | グラファイト / 密度波 / 強磁場 |
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| Outline of Final Research Achievements |
Graphite is a semimetal that consists of carbon atoms, and is known to undergo magnetic-field-induced phase transitions at low temperatures and high magnetic fields along the c-axis. These transitions are observed as abrupt resistance changes, and are interpreted as the occurrence of a spin- or charge- density wave along the c-axis. Besides, it has been well believed that the density wave state is terminated at 53 T, above which graphite is in its normal phase.
We have investigated the longitudinal magnetoresistance of graphite in magnetic fields of up to 75 T and found strong indications of the field-induced phase even above 53 T. We have also investigated the current-voltage characteristics in magnetic fields of up to 56 T, with the intention of obtaining more concrete evidence for density wave states, and observed non-linear transport well above 53 T. Consequently, we suggest that another field-induced state is stabilized above 53 T, which may be regarded as an excitonic phase.
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