%0 Journal Article
%A Niklowitz, P. G.
%A Dunsiger, S. R.
%A Pfleiderer, C.
%A Link, P.
%A Schneidewind, A.
%A Faulhaber, E.
%A Vojta, M.
%A Huang, Y.-K.
%A Mydosh, J. A.
%T Role of commensurate and incommensurate low-energy excitations in the paramagnetic to hidden-order transition of URu$_{2}$Si$_{2}$
%J Physical review / B
%V 92
%N 11
%@ 1098-0121
%C College Park, Md.
%I APS
%M FZJ-2016-01567
%P 115116
%D 2015
%X We report low-energy inelastic neutron scattering data of the paramagnetic (PM) to hidden-order (HO) phase transition at T0=17.5K in URu2Si2. While confirming previous results for the HO and PM phases, our data reveal a pronounced wave-vector dependence of low-energy excitations across the phase transition. To analyze the energy scans we employ a damped harmonic oscillator model containing a fit parameter 1/Γ which is expected to diverge at a second-order phase transition. Counter to expectations the excitations at Q⃗ 1≈(1.4,0,0) show an abrupt steplike suppression of 1/Γ below T0, whereas excitations at Q⃗ 0=(1,0,0), associated with large-moment antiferromagnetism (LMAF) under pressure, show an enhancement and a pronounced peak of 1/Γ at T0. Therefore, at the critical HO temperature T0, LMAF fluctuations become nearly critical as well. This is the behavior expected of a “supervector” order parameter with nearly degenerate components for the HO and LMAF leading to nearly isotropic fluctuations in the combined order-parameter space.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000360885100005
%R 10.1103/PhysRevB.92.115116
%U https://juser.fz-juelich.de/record/281911