Emergent magnetic behavior in the frustrated Yb3 Ga5 O12 garnet

We report neutron scattering, magnetic susceptibility and Monte Carlo theoretical analysis to verify the short-range nature of the magnetic structure and spin-spin correlations in a Yb3 Ga5 O12 single crystal. The quantum spin state of Yb3+ in Yb3 Ga5 O12 is verified. The quantum spins organize into a short-ranged emergent director state for T < 0.6 K derived from anisotropy and near-neighbor exchange. We derive the magnitude of the near-neighbor exchange interactions 0.6 < J 1 < 0.7 K, J2 = 0.12 K and the magnitude of the dipolar exchange interaction, D, in the range 0.18 < D < 0.21 K. Certain aspects of the broad experimental dataset can be modeled using a J 1 D model with ferromagnetic near-neighbor spin-spin correlations while other aspects of the data can be accurately reproduced using a J1J2D model with antiferromagnetic near-neighbor spin-spin correlation. As such, although we do not quantify all the relevant exchange interactions, we nevertheless provide a strong basis for the understanding of the complex Hamiltonian required to fully describe the magnetic state of Yb3 Ga5 O12.