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Analysis of f-p model for octupole ordering in NpO2

Katsunori Kubo·Takashi Hotta
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Abstract

In order to examine the origin of octupole ordering in NpO2, we propose a microscopic model constituted of neptunium 5f and oxygen 2p orbitals. To study multipole ordering, we derive effective multipole interactions from the f-p model by using the fourth-order perturbation theory in terms of p-f hopping integrals. Analyzing the effective model numerically, we find a tendency toward Γ_{5u} antiferro-octupole ordering.

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Katsunori Kubo, Takashi Hotta. 2005-10-27. Analysis of f-p model for octupole ordering in NpO2. https://doi.org/10.1103/physrevb.72.132411

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