Report
Role of commensurate and incommensurate low-energy excitations in the paramagnetic to hidden-order transition of URu$_2$Si$_2$
| العنوان: | Role of commensurate and incommensurate low-energy excitations in the paramagnetic to hidden-order transition of URu$_2$Si$_2$ |
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| المؤلفون: | Niklowitz, P. G., Dunsiger, S. R., Pfleiderer, C., Link, P., Schneidewind, A., Faulhaber, E., Vojta, M., Huang, Y. -K., Mydosh, J. A. |
| المصدر: | Phys. Rev. B 92, 115116 (2015) |
| سنة النشر: | 2011 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons |
| الوصف: | We report low-energy inelastic neutron scattering data of the paramagnetic (PM) to hidden-order (HO) phase transition at $T_0=17.5\,{\rm K}$ in URu$_2$Si$_2$. While confirming previous results for the HO and PM phases, our data reveal a pronounced wavevector 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 $1/\Gamma$ which is expected to diverge at a second-order phase transition. Counter to expectations the excitations at $\vec{Q}_1=(1.44,0,0)$ show an abrupt step-like suppression of $1/\Gamma$ below $T_0$, whereas excitations at $\vec{Q}_0=(1,0,0)$, associated with large-moment antiferromagnetism (LMAF) under pressure, show an enhancement and a pronounced peak of $1/\Gamma$ at $T_0$. Therefore, at the critical HO temperature $T_0$, LMAF fluctuations become nearly critical as well. This is the behavior expected of a super-vector order parameter with nearly degenerate components for the HO and LMAF leading to nearly isotropic fluctuations in the combined order-parameter space. Comment: 6 pages; v3 accepted journal version; minor modifications compared to v2 |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.92.115116 |
| URL الوصول: | http://arxiv.org/abs/1110.5599 |
| رقم الانضمام: | edsarx.1110.5599 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevB.92.115116 |
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