Spin-liquid versus dimer phases in an anisotropicJ1-J2frustrated square antiferromagnet

Abstract

The spin-1/2 ${J}_{1}$-${J}_{2}$ antiferromagnet is a prototypical model for frustrated magnetism and one possible candidate for a realization of a spin-liquid phase. The generalization of this system on the anisotropic square lattice is given by the ${J}_{1}$-${J}_{2}$-${J}_{1}^{\ensuremath{'}}$-${J}_{2}^{\ensuremath{'}}$ Heisenberg model, which can be treated by a renormalization group analysis of coupled frustrated chains. The ${J}_{1}$-${J}_{2}$-${J}_{1}^{\ensuremath{'}}$-${J}_{2}^{\ensuremath{'}}$-model shows an interesting interplay of N\'eel order, dimerization, and spin-liquid behavior. Extrapolating the analytical findings supported by numerical results indicates that for the isotropic model the phase at intermediate coupling strength $0.4{J}_{1}\ensuremath{\lesssim}{J}_{2}\ensuremath{\lesssim}0.6{J}_{1}$ is not a spin liquid, but has instead a staggered dimer order.