ヘリカルマグネットの実験結果と一致するモデル化された挙動。 Modeled behavior consistent with results from helical magnet experiments
2023-04-09 ライス大学
◆これに対し、アイオワ州立大学のアメス国立研究所の実験物理学者マカリー・タナター氏が、ヘリマグネットの層状結晶における困惑する電子的振る舞いに注目し、この謎をネビドムスキー氏に相談。彼らは計算モデルを作成し、物質内の原子および電子の量子状態をシミュレーションした。
◆この結果、物質が磁気秩序から磁気無秩序への移行過程で中間状態を通過し、シート内の磁気双極子の相互作用がシート間の相互作用よりも強くなることで、磁気液体のパンケーキが生じたという。
＜関連情報＞
- https://news.rice.edu/news/2023/physicists-discover-stacked-pancakes-liquid-magnetism
- https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.166701
フラストアイシング反強磁性体の異方的融解を発見 Anisotropic Melting of Frustrated Ising Antiferromagnets
Matthew W. Butcher, Makariy A. Tanatar, and Andriy H. Nevidomskyy
Physical Review Letters Published 19 April 2023
DOI:https://doi.org/10.1103/PhysRevLett.130.166701
ABSTRACT
Magnetic frustrations and dimensionality play an important role in determining the nature of the magnetic long-range order and how it melts at temperatures above the ordering transition TN. In this Letter, we use large-scale Monte Carlo simulations to study these phenomena in a class of frustrated Ising spin models in two spatial dimensions. We find that the melting of the magnetic long-range order into an isotropic gaslike paramagnet proceeds via an intermediate stage where the classical spins remain anisotropically correlated. This correlated paramagnet exists in a temperature range TN<T<T∗, whose width increases as magnetic frustrations grow. This intermediate phase is typically characterized by short-range correlations; however, the two-dimensional nature of the model allows for an additional exotic feature—formation of an incommensurate liquidlike phase with algebraically decaying spin correlations. The two-stage melting of magnetic order is generic and pertinent to many frustrated quasi-2D magnets with large (essentially classical) spins.
