Variational Monte Carlo study of Mott transitions based on theories of Kohn and Berry phase
| Project/Area Number |
25400351
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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 | Tohoku University |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
OGATA Masao 東京大学, 大学院理学系研究科, 教授 (60185501)
KOBAYASHI Kenji 千葉工業大学, 工学部, 教授 (50225504)
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| Research Collaborator |
TAMURA Shun 名古屋大学, 大学院工学研究科, PD研究員
SATO Ryo 東北大学, 大学院理学研究科
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| Project Period (FY) |
2013-04-01 – 2017-03-31
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| Project Status |
Completed (Fiscal Year 2016)
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| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2013: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Keywords | モット転移 / ドゥルーデ重み / 位相因子 / 変分モンテカルロ法 / 交替磁束状態 / 擬ギャップ / 局所環電流 / 反強磁性 / 強相関 / パイエルス位相 / 局在長 / 配置依存位相因子 / フラックス状態 / 局所的循環電流 |
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| Outline of Final Research Achievements |
Properties of conductor-insulator (Mott) transitions owing to electron correlation were studied, using numerical calculations based on a many-body variation theory. We theoretically resolved a long-standing problem of a useful index for conductivity, Drude weight, by combining Kohn's method with introduction of configuration-dependent phase factor into the wave function. This scheme was successfully applied to a local current state, and a theoretical contradiction in stability of the staggered flux state was resolved.
We also calculated localization length of Mott insulators on the basis of Berry-phase theory. As a result, it was shown that we can usefully determine Mott-transition points with this scheme. Furthermore, we performed a series of calculations by introducing band-renormalization effects for doped Mott insulators, and showed that antiferromagnetic states become extremely stable.
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Report
(5 results)
Research Products
(73 results)
