Crystal fields and magnetic structure of the Ising antiferromagnet Er3Ga5O12

Abstract

Rare earth garnets are an exciting playground for studying the exotic magnetic properties of the frustrated hyperkagome lattice. Here we present a comprehensive study of the single ion and collective magnetic properties of the garnet Er3Ga5O12. Using inelastic neutron scattering, we find a crystal field ground state doublet for Er 3+ with strong Ising anisotropy along local [100] axes. Magnetic susceptibility and heat capacity measurements provide evidence for long-range magnetic ordering with TN = 0.8 K, and no evidence for residual entropy is found when cooling through the ordering transition. Neutron powder diffraction reveals that the ground state spin configuration corresponds to the six-sublattice, Ising antiferromagnetic state (Γ3) common to many of the rare earth garnets. Our results indicate that Er3Ga5O12 is an excellent model system for studying the complex metamagnetism expected for a multi-axis antiferromagnet.

Dynamical Scaling of Charge and Spin Responses at a Kondo Destruction Quantum Critical Point

“…The model is studied using a continuous-time Quantum Monte Carlo (CT-QMC) method developed in Ref. [29] (see also Refs. [30][31][32][33][34]).…”

“…In the large-N limit, a QCP separates the strongcoupling Kondo phase from a Kondo destruction critical phase. In the SU(2) model, for the value of s we focus on, the Kondo destruction phase also corresponds to a critical phase [29]. Comparing the critical properties of the dynamical large-N limit with the SU(2) model allows us to assess the degree to which 1/N corrections modify the leading quantum critical singularities.…”

“…Still, by using the algorithm recently developed in Ref. [29], we are able to reach low-enough temperatures and a sufficiently large dynamical range in τ to determine the scaling properties in the quantum critical regime. We see from Fig.…”

“…The model itself is standard, as is the EDMFT approach [19]. However, systematic calculations for the SU(2)-symmetric case has only become possible recently with the advent of the SU(2) CT-QMC method [29]. Within EDMFT the lattice model is described by the BFKM involving selfconsistently determined bath.…”

Emergent magnetic behavior in the frustrated Yb3Ga5O12 garnet

“…Furthermore, as the temperature is reduced below T < 0.175 K, GGG enters a spin slush state, a coexistence of longer-range, solidlike and shorter-range, liquidlike correlations [7], which has theoretically been shown to require the inclusion of the very-long-range nature of the dipolar interactions [8] and interhyperkagome exchange. The director and spin slush states in GGG can be contrasted with the unusual long-range magnetic structures observed in the isostructural compounds Tb 3 Gd 5 O 12 (TGG) and Er 3 Al 5 O 12 (ErAG) [9,10] for T T N = 0.25 and 0.8 K, respectively. Both compounds reveal strong local anisotropy resulting in an ordered multiaxis AFM ground state.…”