Related papers: Quantum Monte Carlo simulation of overpressurized …
Molecular para-hydrogen has been proposed theoretically as a possible candidate for superfluidity, but the eventual superfluid transition is hindered by its crystallization. In this work, we study a metastable non crystalline phase of bulk…
We present results of the one-body density matrix (OBDM) and the condensate fraction n_0 of liquid 4He calculated at zero temperature by means of the Path Integral Ground State Monte Carlo method. This technique allows to generate a highly…
We have performed a microscopic study of a straight quantized vortex line in three dimensions in condensed $^4$He at zero temperature using the Shadow Path Integral Ground State method and the fixed-phase approximation. We have…
Solid CO2 phase I was studied using the pressure-constant NPT Monte Carlo simulation and the Kihara core potential in the temperature range below 194 K and the pressure range below 10 GPa. At a pressure of 1 bar, the temperature dependence…
Quantum Monte Carlo methods are used to calculate various ground state properties of charged bosons in two dimensions, throughout the whole density range where the fluid phase is stable. Wigner crystallization is predicted at $r_s\simeq…
The hardcore-Bose-Hubbard model with random chemical potential is investigated using quantum Monte Carlo simulation. We consider two cases of random distribution of the chemical potential: a uniformly random distribution and a correlated…
The lattice dynamics of hcp crystalline 4He is studied at zero temperature and for two different densities (near and far from melting), using a ground-state path-integral quantum Monte Carlo technique. The complete phonon dispersion is…
We present a diffusion Monte Carlo study of a vortex line excitation attached to the center of a $^4$He droplet at zero temperature. The vortex energy is estimated for droplets of increasing number of atoms, from N=70 up to 300 showing a…
The high-pressure II-III phase transition in solid hydrogen is investigated using the random phase approximation and diffusion Monte Carlo. Good agreement between the methods is found confirming that an accurate treatment of exchange and…
We introduce an efficient scheme for the molecular dynamics of electronic systems by means of quantum Monte Carlo. The evaluation of the (Born-Oppenheimer) forces acting on the ionic positions is achieved by two main ingredients: i) the…
A theoretical study is reported of the molecular-to-atomic transition in solid hydrogen at high pressure. We use the diffusion quantum Monte Carlo method to calculate the static lattice energies of the competing phases and a…
Diffusion Monte Carlo results for the phonon-roton excitation branch in bulk liquid $^4$He at zero temperature are presented. The sign problem associated to the excited wave function has been dealt both with the fixed-node approximation and…
We present a first-principles study of the energy and elastic properties of solid helium at pressures below the range in which is energetically stable. We find that the limit of mechanical stability in hcp 4He is $P_{s}$ = -33.82 bar, which…
We have studied the solubility of molecular hydrogen in bulk liquid $^4$He at zero temperature using the diffusion Monte Carlo method and realistic interatomic potentials between the different species of the mixture. Around the $^4$He…
The study of the high pressure phase diagram of hydrogen has continued with renewed effort for about one century as it remains a fundamental challenge for experimental and theoretical techniques. Here we employ an efficient molecular…
The low-temperature properties of a 2D Bose fluid of charged particles interacting through a 1/r potential, moving in the presence of a uniform neutralizing background, is studied by Quantum Monte Carlo simulations. We make use of the…
The dynamic structure factor of superfluid $^4$He has been investigated at very low temperatures by inelastic neutron scattering. The measurements combine different incoming energies resulting in an unprecedentedly large dynamic range with…
We survey the phase diagram of high-pressure molecular hydrogen with path integral molecular dynamics using a machine-learned interatomic potential trained with Quantum Monte Carlo forces and energies. Besides the HCP and C2/c-24 phases, we…
We investigate the dynamic structure factor of a system of Bose particles at zero temperature using quantum Monte Carlo methods. Interactions are modeled using a hard-sphere potential of size $a$ and simulations are performed for values of…
We have carried out a microscopic study of the dynamic structure factor of liquid $^4$He across the normal-superfluid transition temperature using the path integral Monte Carlo method. The ill-posed problem of the inverse Laplace transform,…