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

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.

4 pages, 1 eps figure; proceedings of the symposium on "Spin- and charge-correlations in molecule-based materials", October 2005, Koenigstein (Taunus), Germany

References in corpus (5)

• Electron Spin Resonance in S=1/2 antiferromagnetic chains
• Persistent spin currents in mesoscopic Heisenberg rings
• Instability of antiferromagnetic magnons in strong fields
• Magnetic properties of a metal-organic antiferromagnet on a distorted honeycomb lattice
• Spin-wave interactions in quantum antiferromagnets

Cited by in corpus (4)

• Quantum Heisenberg antiferromagnets in a uniform magnetic field: nonanalytic magnetic field dependence of the magnon spectrum
• Magnetic Catalysis in Antiferromagnetic Films
• Square-Lattice Antiferromagnet Subjected to a Magnetic Field Aligned with the Order Parameter
• Spin dynamics of antiferromagnets in the presence of a homogeneous magnetization