Nonuniform spin configurations in a uniaxial antiferromagnet

Abstract

The low-energy spin configurations of a simple, uniaxial antiferromagnet have been determined for applied fields both above and below the critical field for the spin-flop transition. The stability of the states has been examined. It is shown that the uniform antiparallel state becomes unstable well below the critical field. The lowest-energy nonuniform configuration is described in detail for all relevant applied-field regions. Higher-energy states are also described and examined for stability. It is shown that some higher-energy states containing both anitiparallel and spin-flopped regions are locally stable.