Sigma models on curved space and bubble refraction in doped antiferromagnets
Sigma models on curved space and bubble refraction in doped antiferromagnets
The dynamics of bubble solitons in two-dimensional isotropic antiferromagnets, inhomogeneously doped so that the exchange integral J becomes position-dependent, is studied. In the usual continuum approximation, the system reduces to a nonlinear sigma model on a spacetime whose geometry depends on J(x). It is shown, both within the geodesic approximation, …