Similarity of thermodynamic properties of the Heisenberg model on triangular and kagome lattices

Derivation of a reduced effective model allows for a unified treatment and discussion of the J₁-J₂4pt0exS=1/2 Heisenberg model on triangular and kagome lattices. Calculating thermodynamic quantities, i.e., the entropy $s(T)$ and uniform susceptibility χ₀(T), numerically on systems up to effectively $N=42$ sites, we show by comparing to full-model results that low-T properties are qualitatively well represented within the effective model. Moreover, we find in the spin-liquid regime similar variation of $s(T)$ and χ₀(T) in both models down to TJ₁. In particular, studied spin liquids appear to be characterized by the Wilson ratio vanishing at low T, indicating that the low-lying singlets are dominating over the triplet excitations.