Solitons in a class of systems of two coupled real scalar fields

This paper deals with systems of two coupled real scalar fields in bidimensional spacetime. We show that when the potential that specifies the system presents a particular form, we are led to first-order equations that solve the second-order equations of motion for static fields. The first-order equations can be seen as a dynamical system, and the static classical solutions present minimum energy, and are classically stable. We consider explicit examples to illustrate the general procedure. In particular, we introduce a specific system that can be used to model ferroelectric crystals.