Related papers: Metastable Ultracondensed Solid Hydrogenous Materi…
Dynamic compression has been used to synthesize liquid metallic hydrogen at 140 GPa (1.4 million bar) and experimental data and theory predict Al2O3 might be a metallic glass at ~300 GPa. The mechanism of metallization in both cases is…
Eremets and Troyan recently reported a transition of molecular hydrogen to metallic hydrogen (MH) at a pressure of ~270 GPa and 300 K. The quest for MH has been going on since 1935 when Wigner and Huntington predicted solid H2 at 0 K would…
Solid hydrogen sulfide is well known as a typical molecular crystal but its stability under pressure is still under debate. Particularly, Eremets et al. found the high pressure superconductivity with $T_{c}\approx$ 190 K in a H$_{2}$S…
A torsional oscillator study of solid para-hydrogen has been carried out down to 20 mK in search for evidence of superfluidity. This work was inspired by the observation of the supersolid phase in solid He-4. We found evidence of a possible…
Supersolid is a mysterious and puzzling state of matter whose possible existence has stirred a vigorous debate among physicists for over 60 years. Its elusive nature stems from the coexistence of two seemingly contradicting properties,…
Superconducting metamaterials are utilized to study the approach to the plasmonic limit simply by tuning temperature to modify the superfluid density, and thus the superfluid plasma frequency. We examine the persistence of artificial…
The interplay between electron correlation and nuclear quantum effects makes our understanding of elemental hydrogen a formidable challenge. Here, we present the phase diagram of hydrogen and deuterium at low temperatures and high-pressure…
Hydrogen and hydrides materials have long been considered promising materials for high-temperature superconductivity. But the extreme pressures required for the metallization of hydrogen-based superconductors limit their applications. Here,…
Recent discoveries of superconductivity in hydrogen-rich compounds stabilized by high pressures have shown that a critical temperature of superconductivity Tc can reach near room temperature values. The current studies focus on the search…
Recently, an extremely high superconducting temperature (Tc) of ~200 K has been reported in the sulfur hydride system above 100 GPa. This result is supported by theoretical predictions and verified experimentally. The crystal structure of…
The theoretical maximum critical temperature ($T_c$) for conventional superconductors at ambient pressure remains a fundamental question in condensed matter physics. Through analysis of electron-phonon calculations for over 20,000 metals,…
We develop a one-dimensional mathematical model for the loading process of hydrogen in a metal hydride tank. The model describes the evolution of the density and pressure of the hydrogen gas, the temperature of the tank, the averaged…
Various mechanisms have been proposed for hydrogen embrittlement, but the causation of hydrogen-induced material degradation has remained unclear. This work shows hydrogen embrittlement due to phase instability (decomposition). In-situ…
The properties of some forms of water ice reserve still intriguing surprises. Besides the several stable or metastable phases of pure ice, solid mixtures of water with gases are precursors of other ices, since in some cases they may be…
The abundant chemical compositions in ternary hydrides bring much more possibility to explore high temperature superconductors under lower pressure. Here we constructed 115 ternary hydrides on the basis of the elements substitution using 16…
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…
Although hydrogen is the simplest of atoms, it does not form the simplest of solids or liquids. Quantum effects in these phases are considerable (a consequence of the light proton mass) and they have a demonstrable and often puzzling…
Hydrogen at high temperature and pressure undergoes a phase transition from a liquid molecular phase to a conductive atomic state, or liquid metallic hydrogen, sometimes referred to as the plasma phase transition (PPT). The PPT phase line…
Following the idea that hydrogen-rich compounds might be high-T$_c$ superconductors at high pressures, and the very recent breakthrough in predicting and synthesizing hydrogen sulfide with record-high T$_c$ = 203 K, ab initio evolutionary…
The discovery of a record high superconducting transition temperature (Tc) of 288 K in a pressurized hydride inspires new hope to realize ambient condition superconductivity. Here, we give a perspective on the theoretical and experimental…