Competing interactions in the XYZ model
  We study the interplay between a XY anisotropy $\gamma$, exchange modulations and an external magnetic field along the z direction in the XYZ chain using bosonization and Lanczos diagonalization techniques. We find an Ising critical line in the space of couplings which occur due to competing relevant perturbations which are present. More general situations are also discussed. 
M.Arlego, D.C.Cabra, J.E.Drut, M.D.Grynberg