Investigation of exotic quantum phenomena on strongly correlated electron materials without inversion symmetry in their crystal structures under ultra high pressure

2019 Fiscal Year Final Research Report

• Project/Area Number: 15K05156
• 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: Tohoku University
• Principal Investigator: HONDA FUMINORI 東北大学, 金属材料研究所, 准教授 (90391268)
• Co-Investigator(Kenkyū-buntansha): 青木 大 東北大学, 金属材料研究所, 教授 (30359541)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: 圧力下物性 / 強相関電子系 / 純良単結晶 / フラストレーション磁性 / 超伝導 / 圧力誘起価数転移 / 量子臨界現象

Outline of Final Research Achievements

The rich variety of f-electron compounds provides an ample opportunity for systematic studies of their characteristic electronic states. In order to unveil the mechanisms of those properties, pressure study is a powerful tool, where the inter atomic distances and various interactions can be tuned precisely. The electronic properties of several rare-earth and actinide compounds without inversion symmetry in their crystal structure have been investigated under ambient and high pressures. Exotic electronic properties such as, pressure induced valence transition, enhancement/suppression of magnetism etc. were observed. Besides a new type of diamond anvil type pressure cell is also constructed for SQUID magnetometer. It will be quite useful for quick survey of the stability of ferromagnet and superconductors under high pressures.

Free Research Field

固体物理

Academic Significance and Societal Importance of the Research Achievements

結晶構造に反転対称性のない物質の新奇量子相や遍歴的なd電子と局在的な4f電子の中間の電子状態と言える5f電子が示す遍歴的な多極子の物理は強相関電子系分野の研究者が注目している。本研究の進展により、大きなスピン-軌道相互作用が重要なキーとなるアクチノイド化合物に関する結晶構造と物性（磁性・超伝導）に関する知見を得ることができた。もっぱら核エネルギーとして注目されるウランという元素の、他の元素では見られないとても興味深い基礎科学的な一面を明らかにすることは、社会的にも意義があると考える。