Itinerant spin excitations near the hidden order transition in URu2Si2

Published

April 22, 2009

Author(s)

J. A. Janik, H. D. Zhou, Y.-J. Jo, L. Balicas, G. J. MacDougall, G. M. Luke, J. D. Garrett, K. J. McClellan, E. D. Bauer, J. L. Sarrao, Yiming Qiu, John R. Copley, Z. Yamani, W. J. Buyers, C. R. Wiebe

Abstract

By means of neutron scattering we show that the high-temperature precursor to the hidden order state of the heavy fermion superconductor URu₂Si₂ exhibits heavily damped incommensurate paramagnons whose strong energy dispersion is very similar to that of the long-lived longitudinal f-spin excitations that appear below T₀. Since the underlying local f-exchange is preserved we expect only the f-d interactions to change across the phase transition and to cause the paramagnetic damping. The damping exhibits single-ion behavior independent of wave vector and vanishes below the hidden order transition. We suggest that this arises from a transition from valence fluctuations to a hybridized f-d state below T₀. Here we present evidence that the itinerant excitations, like those in chromium, are due to Fermi surface nesting of hole and electron pockets so that the hidden order phase likely originates from a Fermi-surface instability. We identify wave vectors that span nested regions of a band calculation and that match the neutron spin crossover from incommensurate to commensurate on approach to the hidden order phase.

Citation

Journal of Physics: Condensed Matter

Volume

21

Issue

19

Pub Type

Journals

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Keywords

heavy fermion, spin excitation, inelastic neutron scattering

Citation

Janik, J. , Zhou, H. , Jo, Y. , Balicas, L. , MacDougall, G. , Luke, G. , Garrett, J. , McClellan, K. , Bauer, E. , Sarrao, J. , Qiu, Y. , Copley, J. , Yamani, Z. , Buyers, W. and Wiebe, C. (2009), Itinerant spin excitations near the hidden order transition in URu2Si2, Journal of Physics: Condensed Matter, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=610024 (Accessed July 18, 2024)