Related papers: Conductivity and Dissociation in Metallic Hydrogen…
Recently, the claim of room-temperature superconductivity in nitrogen-doped lutetium hydride at near-ambient conditions has attracted tremendous attention. Criticism of the work rises shortly, while further explorations are needed to settle…
Recently, several research groups announced reaching the point of metallization of hydrogen above 400 GPa. Following the mainstream of extensive investigations of compressed polyhydrides, in this work we demonstrate that small (4 atom %)…
Experimental investigation of hydrodynamics in electron fluids is a highly topical research area that emerged during the last few years. A recent measurement of the optical conductivity in graphene [P. Gallagher et.al, Science 364, 158…
Damped Lyman-$\alpha$ absorbers (DLAs) with molecular hydrogen have been probed in detail through both spectroscopic observations and numerical modelling. However, such H$_2$ absorbers are quite sparse at very high redshifts. We identify…
Behaviours of hydrogen, such as fluidity and metallicity, are crucial for our understanding of planetary interiors and the emerging field of high-temperature superconducting hydrides. These behaviours were discovered in complex phase…
Two new phases of hydrogen have been discovered at room temperature in Ref.1: phase IV above 220 GPa and phase V above ~270 GPa. In the present work we have found a new phase VI at P~360 GPa and T<200 K. This phase is likely metallic as…
In this work, we report on the atom probe tomography analysis of two metallic hydrides formed by pressurized charging using an ex situ hydrogen charging cell, in the pressure range of 200-500 kPa (2-5 bar). Specifically we report on the…
We present first-principles calculations of metallic atomic hydrogen in the 400-600 GPa pressure range in a tetragonal structure with space group $I4_1/amd$, which is predicted to be its first atomic phase. Our calculations show a band…
The optical spectra of hydrogen at $\sim$500 GPa were studied theoretically using a combination of \emph{ab initio} methods. Among the four most competitive structures, i.e. C2/c-24, Cmca-12, Cmca-4, and I41/amd, only the atomic phase…
We have extended the range of the high-pressure optical spectroscopy to the far-infrared region keeping the accuracy of ambient-pressure experiments. The newly-developed method offers a powerful tool for the study of pressure-induced phase…
Management of heat during charging and discharging of Li-ion batteries is critical for their safety, reliability, and performance. Understanding the thermal conductivity of the materials comprising batteries is crucial for controlling the…
Rare-earth hydrides can exhibit high-temperature superconductivity under high pressure. Here, we apply a crystal structure prediction method to the current record-holding $T_c$ material, LaH$_{10}$, and a candidate for even higher $T_c$,…
A model of the collisional kinetics of energetic hydrogen atoms, molecules, and ions in pure H$_2$ discharges is used to predict H$_\alpha$ emission profiles and spatial distributions of emission from the cathode regions of low-pressure,…
The optical properties of a V4O7 single crystal have been investigated from the high temperature metallic phase down to the low temperature antiferromagnetic insulating one. The temperature dependent behavior of the optical conductivity…
We report the first experimental evidence for a metallic phase in fluid molecular oxygen. Our electrical conductivity measurements of fluid oxygen under dynamic quasi-isentropic compression show that a non-metal/metal transition occurs at…
Metal hydrides often display dramatic changes in optical properties upon hydrogenation. These shifts make them prime candidates for many tunable optical devices, such as optical hydrogen sensors and switchable mirrors. While some of these…
We examine the molecular-atomic transition in liquid hydrogen as it relates to metallization. Pair potentials are obtained from first principles molecular dynamics and compared with potentials derived from quadratic response. The results…
The static electrical conductivity of non-ideal, dense, partially ionized helium plasma was calculated over a wide range of plasma parameters: temperatures $1\cdot 10^{4}\textrm{K} \lesssim T \lesssim 1\cdot 10^{5}\textrm{K}$ and mass…
The low-pressure stabilization of superconducting hydrides with high critical temperatures ($T_c$s) remains a significant challenge, and experimentally verified superconducting hydrides are generally constrained to a limited number of…
The properties of hydrogen-helium mixtures at Mbar pressures and intermediate temperatures (4000 to 10000 K) are calculated with first-principles molecular dynamics simulations. We determine the equation of state as a function of density,…