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arXiv · 1311.3289

Nuclear magnetic resonance studies of pseudospin fluctuations in URu$_2$Si$_2$

K. R. Shirer·J. T. Haraldsen·A. P. Dioguardi·J. Crocker·N. apRoberts-Warren·A. C. Shockley·C. -H. Lin·D. M. Nisson·J. C. Cooley·M. Janoschek·K. Huang·N. Kanchanavatee·M. B. Maple·M. J. Graf·A. V. Balatsky·N. J. Curro
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Abstract

We report $^{29}$Si NMR measurements in single crystals and aligned powders of URu$_2$Si$_2$ in the hidden order and paramagnetic phases. The spin-lattice-relaxation data reveal evidence of pseudospin fluctuations of U moments in the paramagnetic phase. We find evidence for partial suppression of the density of states below 30 K, and analyze the data in terms of a two component spin-fermion model. We propose that this behavior is a realization of a pseudogap between the hidden order transition $T_{HO}$ and 30 K. This behavior is then compared to other materials that demonstrate precursor fluctuations in a pseudogap regime above a ground state with long-range order.

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K. R. Shirer, J. T. Haraldsen, A. P. Dioguardi, J. Crocker, N. apRoberts-Warren, A. C. Shockley, C. -H. Lin, D. M. Nisson, J. C. Cooley, M. Janoschek, K. Huang, N. Kanchanavatee, M. B. Maple, M. J. Graf, A. V. Balatsky, N. J. Curro. 2013-11-13. Nuclear magnetic resonance studies of pseudospin fluctuations in URu$_2$Si$_2$. https://doi.org/10.1103/physrevb.88.094436

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