Melting and orientational order of the screened Wigner crystal on helium films - art. no. 193413

We study the melting of two-dimensional electrons interacting via a screene d Coulomb potential, which describes the interaction between surface electr ons on a helium film coating a solid substrate. We employ the canonical mol ecular-dynamics method to calculate orientational correlation functions in order to determine the nature of the phase transition by varying the screen ing parameter which leads the system from the pure Wigner crystal (electron s on bulk helium) to the dipolar crystal (electrons trapped on a helium fil m over a metal). Our results indicate no evidence of the hexatic phase betw een the solid and liquid phases.