TY  - JOUR
AU  - Niklowitz, P. G.
AU  - Dunsiger, S. R.
AU  - Pfleiderer, C.
AU  - Link, P.
AU  - Schneidewind, A.
AU  - Faulhaber, E.
AU  - Vojta, M.
AU  - Huang, Y.-K.
AU  - Mydosh, J. A.
TI  - Role of commensurate and incommensurate low-energy excitations in the paramagnetic to hidden-order transition of URu$_{2}$Si$_{2}$
JO  - Physical review / B
VL  - 92
IS  - 11
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2016-01567
SP  - 115116
PY  - 2015
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000360885100005
DO  - DOI:10.1103/PhysRevB.92.115116
UR  - https://juser.fz-juelich.de/record/281911
ER  -