Novel quantum magnetism and ferroelectricity induced by geometrical frustration

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K05425
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Momoi Tsutomu 国立研究開発法人理化学研究所, 開拓研究本部, 専任研究員 (80292499)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: スピンネマティック / フラストレート磁性体 / 量子相 / 量子液晶 / 強誘電性 / カゴメ格子 / 超固体

Outline of Final Research Achievements

(1) We theoretically investigated the electron spin resonance (ESR) in a spin nematic phase. Two-magnon excitations inherent in the spin nematic phase can be detected in ESR spectrum via magnetic anisotropy. We also investigated a bi-layer frustrated magnet searching for a spin nematic phase. In a model consisting of two-body interaction only, we have clarified the appearance of the spin nematic phase at zero magnetic field and the mechanism of its appearance.
(2) We investigated various frustrated magnetic materials theoretically, clarifying the appearance of various magnetic phases, thermal Hall effect, and anomalous dynamics.
(3) We clarified the ferro-electricity induced by the correlation effect between spin and orbital degrees of freedom in an orbital degenerate electron system with geometrical frustration.

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

新しい量子相であるスピンネマティック相の出現が理論模型において確かめられ、その出現機構が明らかになった。この相が持つ新奇なふるまいの研究が今後さらに進み新たな研究分野が開拓されるであろう。また、この相の実験による検出方法の提案を行ったことにより、近い将来、実験でこの相の存在が検証されることが期待される。この様に理論と実験の双方における研究の進展が期待される。