Ground-State Properties of the Two-Dimensional Bose Coulomb Liquid

We present results of a ground-state study, via the diffusion Monte Carlo method, of a two-dimensional charged boson liquid. We observe three distinct behaviors in this system. At the lowest densities a close-packed Wigner crystal forms. At $r_s\approx 12$ the crystal melts into a noncondensed liquid exhibiting algebraic off-diagonal long-range order; the single-particle density matrix decays as $r^{-\frac{r_s}{4}}$. Above a threshold density ($r_s<8\mathrm{}$), the long-wavelength momentum distribution diverges as $k^{\frac{(r_s-8)}{4}}$, although no condensate forms.