Prediction of a roton-type feature in warm dense hydrogen

Bound-State Breaking and the Importance of Thermal Exchange–Correlation Effects in Warm Dense Hydrogen

“…In addition to its relevance for ICF compression experiments, such dilute hydrogen can also be realized experimentally in hydrogen jets . The comparably strong electron–electron coupling makes it a potentially challenging test bed for different methods and might give rise to exotic, hitherto unobserved phenomena such as the emergence of a roton-type feature in the dynamic structure factor . Due to the large interatomic distance, the H 2 molecule can easily be identified with the bare eye from the electron density at r s = 4.…”

“…The properties of hydrogen under extreme temperatures and pressures are of prime relevance for numerous applications in both fundamental and applied sciences. It is ubiquitous throughout our universe and constitutes the predominant material in stars and giant planets. , In addition, it is of key importance for technological applications, most notably inertial confinement fusion (ICF). , Despite its apparent simplicity, hydrogen offers a plethora of interesting physical effects at high-energy-density (HED) conditions, including the infamous insulator-to-metal phase transition at high pressure , and a potential roton-type feature in the spectrum of density fluctuations in hydrogen jets. , …”

“…3,4 Despite its apparent simplicity, hydrogen offers a plethora of interesting physical effects at high-energy-density (HED) conditions, including the infamous insulator-to-metal phase transition at high pressure 5,6 and a potential roton-type feature in the spectrum of density fluctuations in hydrogen jets. 7,8 A particularly important property of HED hydrogen is the subsequent breaking of molecular and atomic configurations with increasing densities. This bound state breaking plays an important role in astrophysical models, such as heat transport in Jupiter's atmospheres through H 2 dissociation and recombination.…”

“… 3 , 4 Despite its apparent simplicity, hydrogen offers a plethora of interesting physical effects at high-energy-density (HED) conditions, including the infamous insulator-to-metal phase transition at high pressure 5 , 6 and a potential roton-type feature in the spectrum of density fluctuations in hydrogen jets. 7 , 8 …”

Ab Initio Path Integral Monte Carlo Simulations of the Uniform Electron Gas on Large Length Scales

“…As a second example, we consider the UEG at r s = 10 and Θ = 0.5. These conditions correspond to the boundary of the strongly coupled electron liquid regime , that is known to exhibit a wealth of interesting physical phenomena such as a nonmonotonic roton-type feature in the dynamic structure factor. ,,− In Figure , we show the corresponding SSF and static linear response function with the usual color code. To assess the accuracy of the ξ extrapolation under these conditions, we have carried out new, exact PIMC simulations for N = 14 electrons (green crosses).…”