Interplay between spin-orbit interaction and electron correlation --- analysis based on the first-principles calculations

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540369
• 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: Ritsumeikan University (2014); Kyoto University (2012-2013)
• Principal Investigator: IKEDA Hiroaki 立命館大学, 理工学部, 教授 (90311737)
• Co-Investigator(Kenkyū-buntansha): ARITA Ryotaro 独立行政法人, 理化学研究所・創発物性科学研究センター, チームリーダー (80332592) ; SUZUKI Michi-To 独立行政法人, 理化学研究所・創発物性科学研究センター, 研究員 (10596547)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 重い電子系超伝導 / 隠れた秩序 / 第一原理計算 / 多極子秩序

Outline of Final Research Achievements

In the iron-based superconductors and heavy-electron systems, orbital degrees of freedom can play an important role on the appearance of curious magnetic/multipole ordering and non-BCS superconductivity. However, the complicated band structure, which involves rich physical information, has prevented us from understanding the electronic states so far. Recently, we have succeeded in constructing a low-energy effective Hamiltonian including the spin-orbit interactions. In the model Hamiltonian, we have successfully computed orbital-resolved band structure, Fermi surfaces, and magnetic/multipole susceptibilities. This method is applicable to various materials, and is very useful for understanding the physical properties. Based on this first-principles approach, we found crucial clues to several long-standing mysteries in heavy-electron systems, for instance, the hidden order in URu2Si2 and the first-discovered unconventional superconductivity in CeCu2Si2 and so on.

Free Research Field

物性理論