2015 Fiscal Year Final Research Report
| Project/Area Number |
25400357
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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 Metropolitan University (2015)
The University of Tokyo (2013-2014) |
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Principal Investigator |
UEDA Kazuo 首都大学東京, 理工学研究科, 教授 (70114395)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 強相関電子系 / 量子相転移 / 金属絶縁体転移 / ディラック電子 / スピンギャップ |
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| Outline of Final Research Achievements |
The two-dimensional lattice of the CaV4O9 type is the regularly one-fifth depleted square lattice whose unit cell contains four sites. We have clarified that the Hubbard model on this lattice shows rich variety of metal-insulator transitions as well as magnetic transitions. For this purpose we use the mean field approximation at the quarter filling, while the dynamical mean field theory is employed at the half filling. Difference between the nonmagnetic semiconducting ground state of FeSi and the magnetic metallic one of FeGe is understood in the light of quantum phase transitions in the multi-orbital systems.
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| Free Research Field |
物性理論
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