The Influence of Pauli Blocking Effects on the Mott Transition in Dense Hydrogen

Abstract

We investigate the effects of Pauli blocking on the properties of hydrogen at high pressures. In this region recent experiments have shown a transition from insulating behavior to metal-like conductivity. To describe this transition, several effects have to be taken into account, an important one is the quantum character of the electrons. As electron states can only be occupied once (Pauli blocking), atomic states need more phase space than available at high densities, and bound states disintegrate subsequently (Mott effect). We calculate the energy shifts due to Pauli blocking and discuss the Mott effect solving an effective Schrodinger equation for strongly correlated systems. Additionally, we include corrections due to polarization effects. The ionization equilibrium is treated on the basis of an advanced chemical approach based on the assumption that the system is a gas-like mixture of chemical species. We calculate the Pauli shifts by variational methods and discuss corrections due to polarization. Results for the ionization equilibrium in the region 5,000 < T[K] < 15,000, 0. 1 < ρ[g cm−3] < 1 are presented, where the transition from a neutral hydrogen gas to a highly ionized plasma occurs. We show that the transition to a highly conducting state is softer than predicted in earlier work.