| Project/Area Number |
26800171
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics I
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| Research Institution | Institute of Physical and Chemical Research |
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Principal Investigator |
Shirakawa Tomonori 国立研究開発法人理化学研究所, 創発物性科学研究センター, 研究員 (40571237)
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2014: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
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| Keywords | 磁性不純物 / ディラック電子系 / 密度行列繰り込み群法 / 電子相関 / 近藤効果 |
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| Outline of Final Research Achievements |
We have introduced a numerical technique to study the general impurity problems using the density-matrix renormalization group method. The method has been applied to the effective models for (a) a single adatom on graphene, (b) a substitutional impurity in graphene, and (c) a single carbon vacancy in graphene. We have found that the ground state of the model (i) behaves as an isolated magnetic impurity in a parameter region, while the ground state of the other two models forms a spin-singlet state where the impurity moment is screened by the conduction electrons. We have also established the ground state phase diagram for model (a) in a wide parameter region including the particle-hole asymmetric case, and we have clarified the relation between the impurity quantum phase transition and the entanglement spectrum for the ground state in this system.
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