Related papers: Helium at elevated pressures: Quantum liquid with …
Heat capacity of matter is considered to be its most important property because it holds information about system's degrees of freedom as well as the regime in which the system operates, classical or quantum. Heat capacity is well…
It is generally assumed that solid hydrogen will transform into a metallic alkali-like crystal at sufficiently high pressure. However, some theoretical models have also suggested that compressed hydrogen may form an unusual two-component…
Experiments and computer simulations have shown that the melt-ing temperature of solid hydrogen drops with pressure above about 65 GPa, suggesting that a liquid state might exist at low temperatures. It has also been suggested that this low…
Recently there have been significant theoretical advances in our understanding of liquids and dense supercritical fluids based on their ability to support high frequency transverse (shear) waves. Here, we have constructed a new computer…
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…
The properties of hot dense helium at megabar pressures were studied with two first-principles computer simulation techniques, path integral Monte Carlo and density functional molecular dynamics. The simulations predicted that the…
With regard to the three basic states of matter (solid, liquid, gas), the calculation of the heat capacity of liquids in a general form has been considered one of the deepest and most interesting challenges in condensed matter physics, due…
Recent research shows that liquids and dense supercritical fluids support high frequency shear waves. Here, we proposed a general heat capacity model of supercritical fluids using the latest theoretical findings (the liquid phonon theory).…
The specific heat of liquid helium confined under pressure in nanoporous material and the formation, in these conditions, of a glass phase accompanied by latent heat are known. These properties are in good agreement with a recent model…
By focusing a high intensity acoustic wave in liquid helium, we have observed the nucleation of solid helium inside the wave above a certain threshold in amplitude. The nucleation is a stochastic phenomenon. Its probability increases…
In this paper, with the corresponding formula for internal energy obtained in Ref. [J. Phys. Stud. {\bf 11}, 259 (2007)], combined with a simple calculation of the effective mass of interacting Bose particles, the behavior of the heat…
Superfluidity, liquid flow without friction, is familiar in helium. The first evidence for "supersolidity", its analogue in quantum solids, came from recent torsional oscillator (TO) measurements involving 4-He. At temperatures below 200…
More than half a century ago Penrose asked: are the superfluid and solid state of matter mutually exclusive or do there exist "supersolid" materials where the atoms form a regular lattice and simultaneously flow without friction? Recent…
How high the temperature of a liquid be raised beyond its boiling point without vaporizing (known as the limit of superheat) is an interesting subject of investigation. A new method of finding the limit of superheat of liquids is presented…
Using a functional-integral approach, we have determined the temperature below which cavitation in liquid helium is driven by thermally assisted quantum tunneling. For both helium isotopes, we have obtained the crossover temperature in the…
Equilibrium properties of hydrogen-helium mixtures under thermodynamic conditions found in the interior of giant gas planets are studied by means of density functional theory molecular dynamics simulations. Special emphasis is placed on the…
The energy of a dislocation loop in a continuum elastic solid under pressure is considered within the framework of classical mechanics. For a circular loop, this is a function with a maximum at pressures that are well within reach of…
Hydrogen is the most abundant element in the universe, and its properties under conditions of high temperature and pressure are crucial to understand the interior of of large gaseous planets and other astrophysical bodies. At ultra high…
A concentration-saturated helium mixture at the melting pressure consists of two liquid phases and one or two solid phases. The equilibrium system is univariant, whose properties depend uniquely on temperature. Four coexisting phases can…
Helium (He) is the most inert noble gas at ambient conditions. It adopts a hexagonal close packed structure (P63/mmc) and remains in the insulating phase up to 32 TPa. In contrast, lithium (Li) is one of the most reactive metals at zero…