Origin of the tiny antiferro-magnetic moment in URu2Si2

Citation
A. Tsuruta et al., Origin of the tiny antiferro-magnetic moment in URu2Si2, J PHYS CH S, 62(1-2), 2001, pp. 297-300
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
ISSN journal
0022-3697 → ACNP
Volume
62
Issue
1-2
Year of publication
2001
Pages
297 - 300
Database
ISI
SICI code
0022-3697(200101/02)62:1-2<297:OOTTAM>2.0.ZU;2-L
Abstract
Possible orders in URu2Si2 are investigated using a two-channel degenerate Anderson model. The ground state of uranium ions is the non-Kramers quadrup olar doublet Gamma (5) with (5f)(2), and its relevalent excited state is th e Kramers dipolar doublet Gamma (7) with (5f)(1). These states mix with eac h other via conduction electrons. At low temperatures, the system forms ren ormalized bands with both quadrupole and dipole degrees of freedom due to t he quadrupolar Kondo effect which slightly mixes quadrupolar Gamma (5). a p rimary state of uranium ions, with dipolar Gamma (7) At a certain low tempe rature, conduction electrons in the renormalized bands undergo quadrupolar ordering with a large quadrupolar moment. At a further lower temperature, o ctupolar ordering occurs, accompanied by a tiny dipolar moment which is att ributed to the property of the renormalized bands with primarily the Gamma (5) character slightly mixed with the Gamma (7)-character. These phenomena are well described by the 1/N-expansion method with pseudo-fermions for the non-Kramers doublet Gamma (5) and slave bosons for the Kramers doublet Gam ma (7). (C) 2000 Elsevier Science Ltd. All rights reserved.