Dzyaloshinskii-Moriya Interaction in Spin 1/2 Antiferromagnetic Rings with Nearest Next Neighbor Coupling

We numerically investigate the magnetoelastic(ME)instability in spin 1/2 antiferromagnetic rings with nearest-next neighbor(NNN)coupling J_(2)and Dzyaloshinskii–Moriya(DM)interaction D_(z).It is found that,for a given Dz,there exists a critical J_(2)^(c).As J_(2)=J_(2)^(c),the ME instability is irrelative to the DM interaction and NNN coupling.These results may come from the competition between the DM interaction and NNN coupling.The DM interaction does not affect the critical behavior at the point of J_(2)=0.5,at which the systems always locate in the dimerized state.