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Effective spin-wave action for ordered Heisenberg antiferromagnets in a magnetic field

Nils Hasselmann·Florian Schuetz·Ivan Spremo·Peter Kopietz
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Abstract

We derive the effective long-wavelength Euclidean action for the antiferromagnetic spin-waves of ordered quantum antiferromagnets subject to a uniform magnetic field. We point out that the magnetic field dependence of the spin-wave dispersion predicted by the usual O(3)-quantum nonlinear sigma model disagrees with spin-wave theory. We argue that the nonlinear sigma model does not take into account all relevant spin-wave interactions and derive a modified effective action for the long-wavelength spin-waves which contains an additional quartic interaction. At zero temperature the corresponding vertex is relevant in the renormalization group sense below three dimensions.

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Nils Hasselmann, Florian Schuetz, Ivan Spremo, Peter Kopietz. 2005-11-29. Effective spin-wave action for ordered Heisenberg antiferromagnets in a magnetic field. https://doi.org/10.1016/j.crci.2006.06.008

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