2012/04/30 by H. Ikeda, Hiroaki Ikeda, Michi‐To Suzuki +8 · 150 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Antiferromagnetism #Condensed matter physics #Degenerate energy levels #Iron-based superconductors research #Liquid crystal #Multipole expansion #Phase transition #Physics #Quantum mechanics #Rare-earth and actinide compounds #Symmetry breaking #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1038/nphys2330
published in Nature Physics 8(7), 528-533 (Nature Portfolio) · See the published version with more detailed discussions
openalex publication_date 2012/06/03 · arxiv created 2012/07/18 · arxiv updated 2012/07/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Novel electronic states resulting from entangled spin and orbital degrees of freedom are hallmarks of strongly correlated f-electron systems. A spectacular example is the so-called 'hidden-order' phase transition in the heavy-electron metal URu2Si2, which is characterized by the huge amount of entropy lost at THO=17.5K. However, no evidence of magnetic/structural phase transition has been found below THO so far. The origin of the hidden-order phase transition has been a long-standing mystery in condensed matter physics. Here, based on a first-principles theoretical approach, we examine the complete set of multipole correlations allowed in this material. The results uncover that the hidden-order parameter is a rank-5 multipole (dotriacontapole) order with 'nematic' E- symmetry, which exhibits staggered pseudospin moments along the [110] direction. This naturally provides comprehensive explanations of all key features in the hidden-order phase including anisotropic magnetic excitations, nearly degenerate antiferromagnetic-ordered state, and spontaneous rotational-symmetry breaking.