From incommensurate correlations to mesoscopic spin resonance in YbRh2Si2

COFFEE_KLATCH  · Invited

Abstract

Spin fluctuations are reported near the magnetic field driven quantum critical point in YbRh2Si2 [1]. On cooling, ferromagnetic fluctuations evolve into incommensurate correlations with a characteristic in-plane wave vector of $q_m = (\delta,\delta)$ with $\delta=0.14 \pm 0.04$ r.l.u. At low temperatures, an in plane magnetic field induces a sharp intra doublet resonant excitation at an energy $g\mu_B\mu_0H$ with $g=3.8\pm 0.2$. The intensity is localized at the zone center and has a width in momentum space indicating precession of spin density extending $\xi = 6 \pm 2$ \AA\ beyond the 4f site.\\[4pt] [1] C. Stock, C. Broholm, F. Demmel, J. Van Duijn, J. W. Taylor, H.J. Kang, R. Hu, and C. Petrovic, Phys. Rev. Lett. {\bf 109}, 127201 (2012).

*Work at IQM was supported by DoE, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under Award DE-FG02-08ER46544.

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Authors

  • Collin Broholm

    • Johns Hopkins University / NIST NCNR
    • Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University
    • IQM, JHU; NCNR, NIST; Neutron Science Directorate, ORNL
    • Department of Physics and Astronomy, Johns Hopkins University, Baltimore 21218 MD USA
    • Johns Hopkins University
    • Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA