Bond Operator Mean Field Approach to the Magnetization Plateaux in   Quantum Antiferromagnets -- Application to the S=1/2 Coupled Dimerized Zigzag   Heisenberg Chains
  The magnetization plateaux in two dimensionally coupled S=1/2 dimerized zigzag Heisenberg chains are investigated by means of the bond operator mean field approximation. In the absence of the interchain coupling, this model is known to have a plateau at half of the saturation magnetization accompanied by the spontanuous translational symmetry breakdown. The parameter regime in which the plateau appears is reproduced well within the present approximation. In the presence of the interchain coupling, this plateau is shown to be suppressed. This result is also supported by the numerical diagonalization calculation. 
Kazuo Hida, Masaru Shiino and Wei Chen