Strong exchange anisotropy in YbMgGaO${}_4$ from polarized neutron diffraction

Abstract

We measured the magnetic correlations in the triangular lattice spin-liquid candidate material YbMgGaO${}_4$ via polarized neutron diffraction. The extracted in-plane and out-of-plane components of the magnetic structure factor show clear anisotropy. We found that short-range correlations persist at the lowest measured temperature of 52 mK and neutron scattering intensity is centered at the $M$ middle-point of the hexagonal Brillouin-zone edge. Moreover, we found pronounced spin anisotropy, with different correlation lengths for the in-plane and out-of-plane spin components. When comparing to a self-consistent Gaussian appoximation, our data clearly support a model with only first-neighbor coupling and strongly anisotropic exchanges.

5 pages, 3 figures

Cited by in corpus (2)

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