Hidden order in URu2Si2 originates from Fermi surface gapping induced by dynamic symmetry breaking
2009 (English)In: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 8, no 4, 337-341 p.Article in journal (Refereed) Published
Spontaneous, collective ordering of electronic degrees of freedom leads to second-order phase transitions that are characterized by an order parameter driving the transition. The notion of a 'hidden order' has recently been used for a variety of materials where a clear phase transition occurs without a known order parameter. The prototype example is the heavy-fermion compound URu2Si2, where a mysterious hidden-order transition occurs at 17.5 K. For more than twenty years this system has been studied theoretically and experimentally without a firm grasp of the underlying physics. Here, we provide a microscopic explanation of the hidden order using density-functional theory calculations. We identify the Fermi surface 'hot spots' where degeneracy induces a Fermi surface instability and quantify how symmetry breaking lifts the degeneracy, causing a surprisingly large Fermi surface gapping. As the mechanism for the hidden order, we deduce spontaneous symmetry breaking through a dynamic mode of antiferromagnetic moment excitations.
Place, publisher, year, edition, pages
2009. Vol. 8, no 4, 337-341 p.
IdentifiersURN: urn:nbn:se:uu:diva-129853DOI: 10.1038/NMAT2395ISI: 000264501000027OAI: oai:DiVA.org:uu-129853DiVA: diva2:345513