Power-Law Spin Correlations in a Perturbed Spin Model on a Honeycomb Lattice
We consider the spin-(1)/(2) model on the honeycomb lattice in the presence of a weak magnetic field hα≪1. Such a perturbation destroys the exact integrability of the model in terms of gapless fermions and static Z2 fluxes. We show that it results in the appearance of a long-range tail in the irreducible dynamic spin correlation function: ⟨⟨sz(t,r)sz(0,0)⟩⟩∝hz2f(t,r), where f(t,r)∝[max(t,r)]-4 is proportional to the density polarization function of fermions.
Physical Review Letters
- Pub Date:
- February 2011
- Quantized spin models;
- Condensed Matter - Strongly Correlated Electrons