Bond Operator Mean Field Approach to the Magnetization Plateaux in Quantum Antiferromagnets -- Application to the S=1/2 Coupled Dimerized Zigzag Heisenberg Chains

TL;DR

This paper uses a bond operator mean field approach to study magnetization plateaux in coupled S=1/2 dimerized zigzag Heisenberg chains, revealing how interchain coupling suppresses the plateau and confirming results with numerical diagonalization.

Contribution

It introduces a bond operator mean field method to analyze magnetization plateaux in coupled quantum antiferromagnetic chains, highlighting the effects of interchain coupling.

Findings

Plateau at half saturation magnetization exists without interchain coupling.

Interchain coupling suppresses the magnetization plateau.

Numerical diagonalization supports the mean field results.

Abstract

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.