| Project/Area Number |
18K13502
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
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| Research Institution | Keio University |
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Principal Investigator |
Beekman Aron 慶應義塾大学, 自然科学研究教育センター(日吉), 訪問研究員 (90632985)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2020: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | quantum phase transition / quantum melting / liquid crystals / symmetry breaking / renormalization group / particle-vortex duality / phase transitions / critical exponents / helium |
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| Outline of Final Research Achievements |
Laboratory experiments can deposit helium atoms on graphite substrates with extreme control, and are able to form perfect layers with controllable density, in the low-temperature, quantum regime. These experiments show there may exist a state of planar matter between a solid and a liquid, akin to a liquid crystal. The latter is characterized by preferred directions unlike a featureless liquid. As determining the nature of this state directly is difficult, one may instead obtain information about the transition from the solid to the potentially new, liquid-crystalline state.
To compare with future experimental results, we have studied this quantum phase transition with theoretical methods. In particular, using a duality mapping where lattice vibrations (phonons) are represented as forces (gauge fields), we used the functional renormalization group to determine that this transition should be continuous (second-order). Many avenues for future study have been identified.
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| Academic Significance and Societal Importance of the Research Achievements |
Quantum phase transitions at extremely low temperatures determine physical properties at higher temperatures. The detailed understanding of the quantum solid-to-liquid crystal phase transition allows for more control of various helium states, and impact superfluidity and superconductivity research.
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