Correlations and Coherence at Different Scales (CCDS25)

Recent experiments on novel materials, which are well represented by $S=1/2$ easy-axis spin models on triangular lattice, stimulated renewed theoretical interest in basic properties of anisotropic spin models on frustrated planar lattices. While the thermodynamic properties of the model on the kagome lattices reveal the spin-liquid scenario in the whole range of anisotropies, the case of the triangular lattice is more complex. Spin-wave theory and several numerical studies indicate that
the anisotropic systems should follow the supersolid scenario with ground-state broken translational symmetry and as well the transverse magnetic order, implying the gapless Goldstone mode. Confirming this scenario at finite magnetic fields, we find numerically at zero field the evidence for a solid with a finite gap, reflected in several quantitites. The origin can be traced back to the effects of strong correlations, manifested also in simpler reduced models.