Inhomogeneities in antiferromagnetic solids

We find that in narrow band anti-ferro-magnetic (AF) solids described by general t-J model there may arise electronic molecules or clusters consisting of holes. These holes are segregated around the topological defects such as loops of anti-phase domain walls. The loops are naturally self-organized into the closed loops of triangular, square, rectangular or other form depending on physical situations. This kind of electron molecules is spontaneously formed in AF background and constitute a new type of elementary excitations of the AF solids. We find that the size and shape of these e-molecules depend mostly on the AF coupling J and the bandwidth 4t as well as on the inter-site Coulomb repulsion between holes.