2004/11/30 by Annamaria Kiss, Annamária Kiss, P. Fazekas +1 · 4 citations
Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Field (mathematics) #Hydrostatic equilibrium #Hydrostatic pressure #Mathematical physics #Mathematics #Order (exchange) #Phase (matter) #Phase boundary #Phase diagram #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Rare-earth and actinide compounds #Thermodynamics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.054415
published as Physical Review B 71, Art. No. 054415 (2005) · 23 pages, 7 figures replaced by version accepted by Physical Review B. Changes not extensive but include a change of the title from the original "On the possibility of octupolar order in URu2Si2" to "Group theory and octupolar order in URu2Si2"
openalex publication_date 2005/02/23 · arxiv created 2005/07/21 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Recent experiments on URu2Si2 show that the low-pressure hidden order is nonmagnetic but it breaks time reversal invariance. Restricting our attention to local order parameters of 5f2 shells, we find that the best candidate for hidden order is staggered order of either Tz^\ensuremathβ or Txyz octupoles. Group theoretical arguments for the effect of symmetry-lowering perturbations (magnetic field, mechanical stress) predict behavior in good overall agreement with observations. We illustrate our general arguments on the example of a five-state crystal field model which differs in several details from models discussed in the literature. The general appearance of the mean field phase diagram agrees with the experimental results. In particular, we find that (a) at zero magnetic field, there is a first-order phase boundary between octupolar order and large-moment antiferromagnetism with increasing hydrostatic pressure; (b) arbitrarily weak uniaxial pressure induces staggered magnetic moments in the octupolar phase; and (c) a new phase with different symmetry appears at large magnetic fields.