Kj. Naidoo et J. Schnitker, MELTING OF 2-DIMENSIONAL COLLOIDAL CRYSTALS - A SIMULATION STUDY OF THE YUKAWA SYSTEM, The Journal of chemical physics, 100(4), 1994, pp. 3114-3121
The two-dimensional melting transition of charged polystyrene spheres
in aqueous colloidal suspension has been studied by molecular dynamics
simulation of a screened Coulomb system. Some central predictions of
the Kosterlitz-Thouless-Halperin-Nelson-Young theory of defect-mediate
d melting are confirmed, such as an apparent divergence of the correla
tion lengths for translational and bond-orientational order at differe
nt thermodynamic state points, but there are also predictions of the t
heory that are violated. The defect topology is very complex, with osc
illation periods of the defect density of many million time steps dura
tion. The need for extensive sampling and, to a lesser degree, the cho
ice of potential function continue to be the crucial issues for any at
tempt to generate a hexatic structure by means of computer simulation.