Title: Phase diagram of hydrogen and a hydrogen-helium mixture at planetary conditions by Quantum Monte Carlo simulations,
Abstract: Understanding planetary interiors is directly linked to our ability of
simulating exotic quantum mechanical systems such as hydrogen (H) and
hydrogen-helium (H-He) mixtures at high pressures and temperatures. Equations
of State (EOSs) tables based on Density Functional Theory (DFT), are commonly
used by planetary scientists, although this method allows only for a
qualitative description of the phase diagram, due to an incomplete treatment of
electronic interactions. Here we report Quantum Monte Carlo (QMC) molecular
dynamics simulations of pure H and H-He mixture. We calculate the first QMC EOS
at 6000 K for an H-He mixture of a proto-solar composition, and show the
crucial influence of He on the H metallization pressure. Our results can be
used to calibrate other EOS calculations and are very timely given the accurate
determination of Jupiter's gravitational field from the NASA Juno mission and
the effort to determine its structure.