設計原理は、不変の量子状態を持つ金属の探索の指針となり得る Design principle could guide search for metals with immutable quantum states
2022-09-15 ライス大学
既知の材料に関するデータベースの情報と、現実的な結晶構造に基づく理論計算の結果を相互参照することによって、有望な候補材料を特定する枠組みを開発した。この方法を用いて、研究グループは、近藤効果から生じるトポロジカル状態を保持する可能性の高い3つの物質の結晶構造と元素組成を同定した。
研究対象のモデルと同じ対称性を持つ相関トポロジカルセミメタル材料の設計原理が開発された。
設計原理の有用性は、同定された3つの化合物のうちの1つを作り、それを試験して、予測された特性を持つことを確認したことで実証された。
＜関連情報＞
- https://news.rice.edu/news/2022/physicists-demo-method-designing-topological-metals
- https://www.nature.com/articles/s41567-022-01743-4
強相関と結晶対称性で駆動するトポロジカル半金属 Topological semimetal driven by strong correlations and crystalline symmetry
Lei Chen,Chandan Setty,Haoyu Hu,Maia G. Vergniory,Sarah E. Grefe,Lukas Fischer,Xinlin Yan,Gaku Eguchi,Andrey Prokofiev,Silke Paschen,Jennifer Cano & Qimiao Si
Nature Physics Published:15 September 2022
DOI:https://doi.org/10.1038/s41567-022-01743-4
Abstract
Electron correlations amplify quantum fluctuations and, as such, are recognized as the origin of many quantum phases. However, whether strong correlations can lead to gapless topological states is an outstanding question, in part because many of the ideas in topological condensed-matter physics rely on the analysis of an effectively non-interacting band structure. Therefore, a framework that allows the identification of strongly correlated topological materials is needed. Here we suggest a general approach in which strong correlations cooperate with crystalline symmetry to drive gapless topological states. We test this materials design principle by exploring Kondo lattice models and materials whose space-group symmetries promote different kinds of electronic degeneracies. This approach allows us to identify Weyl–Kondo nodal-line semimetals with nodes pinned to the Fermi energy, demonstrating that it can be applied to discover strongly correlated topological semimetals. We identify three heavy-fermion compounds as material candidates, provide direct experimental evidence for our prediction in Ce2Au3In5 and discuss how our approach may lead to many more. Our findings illustrate the potential of this materials design principle to guide the search for new topological metals in a broad range of strongly correlated systems.
