Correlated impurities and intrinsic spin liquid physics in the kagome material Herbertsmithite

Understand

Low energy inelastic neutron scattering on single crystals of the kagome spin liquid compound ZnCu3(OD)6Cl2 (Herbertsmithite) reveals antiferromagnetic correlations between impurity spins for energy transfers E < 0.8 meV (~J/20).

• The momentum dependence differs significantly from higher energy scattering which arises from the intrinsic kagome spins.
• The low energy fluctuations are characterized by diffuse scattering near wavevectors (1 0 0) and (0 0 3/2), which is consistent with antiferromagnetic correlations between pairs of nearest neighbor Cu impurities on adjacent triangular (Zn) interlayers.
• The corresponding impurity lattice resembles a simple cubic lattice in the dilute limit below the percolation threshold.