Two-dimensional Heisenberg antiferromagnet in strong magnetic fields
Abstract
We calculate magnetization and magnon dispersion for a spin- {1}/{2} Heisenberg square lattice antiferromagnet at T = 0 in magnetic fields up to the saturation field in the framework of spin-wave theory. Magnetic field generally suppresses zero-point fluctuations, which leads to upward curvature of the magnetization curve at low fields and logarithmic singularity close to the saturation. New quantum effects appear due to noncollinearity of the spin structure. They consist of coupling between one- and two-magnon spectrum and affect strongly dispersion of excitations at finite fields.
- Publication:
-
Physica B Condensed Matter
- Pub Date:
- 1997
- DOI:
- 10.1016/S0921-4526(97)00647-9
- Bibcode:
- 1997PhyB..241..573Z