Structure and melting of two-dimensional dust crystals

Dust particles in plasmas confined near the boundary between the plasma bul k and the sheath form a two-dimensional system when appropriate conditions are satisfied. To keep dust particles from running away horizontally, the e lectrostatic potential is usually applied to the electrode surrounding thes e dusty plasmas and we have finite two-dimensional systems of dust particle s. Adopting the Yukawa model for the interaction between dust particles, st ructures of finite two-dimensional Yukawa systems at low temperatures have been analyzed both by molecular dynamics simulations and variational method s. The effect of the correlation energy between dust particles is shown to play an important role in the formation of the one-body distribution in the se systems. Molecular dynamics simulations of large systems typically with 10(3) to 10(4) particles have been performed and the behavior of the mean s quare displacement is obtained for various combinations of characteristic p arameters. The results are discussed in relation to the melting transition on the basis of the theoretical analysis on static structures. (C) 2001 Ame rican Institute of Physics.