Two-Dimensional Hydrogen Structure at Ultra-High Pressure

We introduce a novel method that combines the accuracy of Quantum Monte Carlo simulations with ab-initio Molecular Dynamics, in the spirit of Car-Parrinello. This method is then used for investigating the structure of a two-dimensional layer of hydrogen at $T=0\text{ K}$ and high densities. We find that metallization is to be expected at $r_s\approx 1.1$, with an estimated pressure of $1.0\cdot {10}^3{a}_0\text{ GPa}$, changing from a graphene molecular lattice to an atomic phase.