Statistics of hole pairs in a crystal lattice

The system of coupled hole pairs in a crystal lattice is studied. The exact commutation relations for the hole pair operators correspond to a modified parafermi statistics of rank (M) over bar((M) over bar is the number of si tes in a "superlattice" formed by centers of mass for each hole pair), i.e. one state can be occupied by up to M pairs. Even in the absence of dynamic interaction, the system of hole pairs is characterized by some immanent in teraction (kinematic interaction). In spite of the kinematic interaction, t here is no statistical prohibitions on the Bose-Einstein condensation of co upled hole pairs. (C) 2000 Elsevier Science B.V. All rights reserved.