Ground-state phases of polarized deuterium species

Microscopic prediction of the ground-state phase of electron-spin-aligned bulk atomic deuterium (D{↓}) is attempted, based on the variational Monte Carlo method. The accurate pair potential of Kolos and Wolniewicz is assumed, and three versions of D{↓} are considered, which, respectively, involve one, two, and three equally occupied nuclear spin states. The most definitive results on the zero-temperature equations of state of these systems are obtained with optimized ground-state trial wave functions incorporating Jastrow pair correlations, triplet correlations, and momentum-dependent backflow effects. The species D↓₃ is bound already at the pure Jastrow level, while the energy expectation value of D↓₂ dips below zero upon supplementing the Jastrow description by triplets and momentum-dependent backflow. The variational energy of D↓₁ remains positive under all current refinements of the ground-state trial function. We conclude that the systems D↓₃ and D↓₂, if they could be manufactured and stabilized at relevant densities, would be Fermi liquids at sufficiently low temperature; on the other hand, it is likely that D↓₁ would remain gaseous down to absolute zero.