2004/09/30 by Katsunori Kubo, Takashi Hotta · 4 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Coupling (piping) #Materials science #Multipole expansion #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Rare-earth and actinide compounds #Statistical physics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.140404
published as Phys. Rev. B 71, 140404(R) (2005) · 5 pages, 2 figures
openalex publication_date 2005/04/29 · arxiv created 2005/04/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In order to examine the mysterious ordered phase of NpO2 from a microscopic viewpoint, we investigate an f-electron model on an fcc lattice constructed based on a j\text\ensuremath-j coupling scheme. First, an effective model with multipole interactions is derived in the strong-coupling limit. Numerical analysis of the model clearly indicates that the interactions for \ensuremathΓ4u and \ensuremathΓ5u moments are relevant to the ground state. Then, by applying a mean-field theory to the simplified model including only such interactions, we conclude that the longitudinal triple-q \ensuremathΓ5u octupole order is realized in NpO2 through the combined effects of multipole interactions and anisotropy of the \ensuremathΓ5u moment.