Impurity Effect on the Two-Dimensional-Electron Fluid-Solid Transition in Zero Field

We investigate the effect of impurities on the electron fluid-solid transition with parameters appropriate for the system recently studied by Pudalov et al. The nature of the crystalline state at $T=0\mathrm{}$ in the presence of impurities is studied with the relaxation technique. The solid-fluid transition is studied via perturbation calculation and Monte Carlo simulation. The transition density is found to shift from $r_s\approx 37$ for the pure system to $r_s\approx 7.5$, close to that observed experimentally. At this small value of $r_s$, the fluid energy is sensitive to the spin polarization but the solid is not, suggesting possible interesting magnetic behavior.