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Theory of the field-induced gap in $S=1/2$ antiferromagnetic chains

Masaki Oshikawa·Ian Affleck
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Abstract

In a recent neutron-scattering experiment on the quasi-one-dimensional $S=1/2$ antiferromagnet Cu Benzoate, a gap was induced by an applied magnetic field. We argue that the primary mechanism of the gap formation is an effective staggered field due to both the alternating $g$-tensor and the Dzyaloshinskii-Moriya interaction. We explain the dependence of the gap on the applied field, as well as identify several peaks in the structure factor $S(q,ω)$.

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Masaki Oshikawa, Ian Affleck. 1997-06-10. Theory of the field-induced gap in $S=1/2$ antiferromagnetic chains. https://doi.org/10.1103/physrevlett.79.2883

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