  We study the properties of topological defects in the lattice compact Abelian
Higgs Model with charge Q=2 matter field. We find that monopoles and
antimonopoles form chain-like structures which are dense in the
confinement/symmetric phase. In this phase the mentioned structures explain
both the confinement of single-charged and the breaking of strings spanned
between doubly-charged test particles. This observation helps to understand how
the non-diagonal gluons, once taken into consideration in the Abelian
projection of gluodynamics, could reproduce in this framework the string
breaking for adjoint charges.
