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Coupled $S=1/2$ Heisenberg antiferromagnetic chains in an effective staggered field

Masahiro Sato·Masaki Oshikawa
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Abstract

We present a systematic study of coupled $S=1/2$ Heisenberg antiferromagnetic chains in an effective staggered field. We investigate several effects of the staggered field in the {\em higher} ({\em two or three}) {\em dimensional} spin system analytically. In particular, in the case where the staggered field and the inter-chain interaction compete with each other, we predict, using mean-field theory, a characteristic phase transition. The spin-wave theory predicts that the behavior of the gaps induced by the staggered field is different between the competitive case and the non-competitive case. When the inter-chain interactions are sufficiently weak, we can improve the mean-field phase diagram by using chain mean-field theory and the analytical results of field theories. The ordered phase region predicted by the chain mean-field theory is substantially smaller than that by the mean-field theory.

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Masahiro Sato, Masaki Oshikawa. 2004-01-30. Coupled $S=1/2$ Heisenberg antiferromagnetic chains in an effective staggered field. https://doi.org/10.1103/physrevb.69.054406

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