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).

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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