title: Symmetry of the excitations in the hidden order state of URu2Si2.
abstract: We perform polarized electronic Raman scattering on URu2Si2 single crystals at low temperature down to 8 K in the hidden-order state and under a magnetic field up to 10 T. The hidden-order state is characterized by a sharp excitation at 1.7 meV and a gap in the electronic continuum below 6.8 meV. Both Raman signatures are of pure A2g symmetry. By comparing the behavior of the Raman sharp excitation and the neutron resonance at Q0=(0,0,1), we provide new evidence, constrained by selection rules of the two probes, that the hidden-order state breaks the translational symmetry along the c axis such that Γ and Z points fold on top of each other. The observation of these distinct Raman features with a peculiar A2g symmetry as a signature of the hidden-order phase places strong constraints on current theories of the hidden-order in URu2Si2.
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France.
authors.forename: J
authors.initials: J
authors.lastname: Buhot
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France.
authors.forename: M-A
authors.initials: MA
authors.lastname: Méasson
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Gallais
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France.
authors.forename: M
authors.initials: M
authors.lastname: Cazayous
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France.
authors.forename: A
authors.initials: A
authors.lastname: Sacuto
authors.affiliation: Université Grenoble Alpes, INAC-SPSMS, F-38000 Grenoble, France and CEA, INAC-SPSMS, F-38000 Grenoble, France.
authors.forename: G
authors.initials: G
authors.lastname: Lapertot
authors.affiliation: Université Grenoble Alpes, INAC-SPSMS, F-38000 Grenoble, France and CEA, INAC-SPSMS, F-38000 Grenoble, France.
authors.forename: D
authors.initials: D
authors.lastname: Aoki