POLARON-LIKE FEATURES OF THE DOMAIN-WALL IN A CLASSICAL ISING CHAIN WITH TRANSVERSE FIELD

The possibility of the creation of the bound state of a domain wall an d surrounding lattice distortion was investigated in the framework of the one-dimensional Ising model with transverse field. It was found th at the existence of such an entity is very sensitive to the mutual rat io of the basic physical parameters of the system. We obtain that, in the weak-coupling regime, such a 'dressed' excitation can arise in the so-called unadiabatic limit when the maximal phonon energy greatly ex ceeds the nearest-neighbour exchange energy. In that case, the 'dressi ng' effect can significantly modify domain-wall properties, causing th e increase of its effective mass and lowering of the ground-state ener gy, while the domain-wall velocity cannot exceed the speed of sound.