DEGENERATE CRYSTALLINE PHASE IN A TWO-DIMENSIONAL SYSTEM OF HARD DIMERS

Monte Carlo simulations showing thermodynamic stability of a non-periodic solid phase in a system of two-dimensional hard, homonuclear dimers are reviewed briefly. The thermodynamic stability of this phase, called degenerate (or disordered) crystal, follows from a huge degeneracy of the close packed structure of the dimers. The degenerate crystalline phase and its various analogues constitute intermediate steps on a path joining periodically ordered crystalline states with completely disordered states of matter.