  We study the formation and control of metastable states of pairs of domain
walls in cylindrical nanowires of small diameter where the transverse walls are
the lower energy state. We show that these pairs form bound states under
certain conditions, with a lifetime as long as 200ns, and are stabilized by the
influence of a spin polarized current. Their stability is analyzed with a model
based on the magnetostatic interaction and by 3D micromagnetic simulations. The
apparition of bound states could hinder the operation of devices.
