Related papers: High pressure melt dynamics in shock-compressed ti…
Ionic structure of high pressure, high temperature fluids is a challenging theoretical problem with applications to planetary interiors and fusion capsules. Here we report a multi-messenger platform using velocimetry and \textit{in situ}…
We present results of an investigation into the formation of nitrogen-bearing molecules in the atmosphere of Titan. We extend a previous model (Li et al. 2015, 2016) to cover the region below the tropopause, so the new model treats the…
We present measurements on Fe$_2$O$_3$ amorphization and melt under laser-driven shock compression up to 209(10) GPa via time-resolved in situ x-ray diffraction. At 122(3) GPa, a diffuse signal is observed indicating the presence of a…
A combination of quantum mechanics calculations with machine learning (ML) techniques can lead to a paradigm shift in our ability to predict materials properties from first principles. Here we show that on-the-fly training of an interatomic…
The thermodynamic behavior of calcium oxide (\ce{CaO}) under high temperature and pressure conditions is critical for understanding the physics of planetary interiors. This study employs molecular dynamics (MD) simulations, including both…
Boron phosphide (BP) is a (super)hard semiconductor constituted of light elements, which is promising for high demand applications at extreme conditions. The behavior of BP at high temperatures and pressures is of special interest but is…
It is challenging to search for high Tc superconductivity (SC) in transition metal elements wherein d electrons are usually not favored by conventional BCS theory. Here we report discovery of surprising SC up to 310 GPa with Tc above 20 K…
The measurement of superconductivity at above 200K in compressed samples of hydrogen sulfide and lanthanum hydride at 250K is reinvigorating the search for conventional high temperature superconductors. At the same time it exposes a…
We introduce a novel method that combines the accuracy of Quantum Monte Carlo simulations with ab-initio Molecular Dynamics, in the spirit of Car-Parrinello. This method is then used for investigating the structure of a two-dimensional…
The high pressure(P)-high temperature(T) phase diagram of solid ammonia has been investigated using diamond anvil cell and resistive heating techniques. The III-IV transition line has been determined up to 20 GPa and 500 K both on…
Compared to the widely investigated crystalline polymorphs of gallium oxide (Ga2O3), knowledge about its amorphous state is still limited. With the help of a machine-learning interatomic potential, we conducted large-scale atomistic…
A constant supply of oxygen has been assumed to be necessary for the growth of titanium nanoparticles by sputtering. This oxygen supply can arise from a high background pressure in the vacuum system or from a purposely supplied gas. The…
The thermodynamic parameters of the superconducting state in Calcium under the pressure at 200 GPa have been determined. The numerical analysis by using the Eliashberg equations in the mixed representation has been conducted. It has been…
Results solving the long standing puzzle regarding the phase diagram and the pressure evolution of the melting temperature Tm(P) of gallium nitride (GaN), the most promising semiconducting material for innovative modern electronic…
The phase stability and transformation between hexagonal close-packed (hcp) {\alpha}-phase and body-centered cubic (bcc) \b{eta}-phase in titanium (Ti) alloys are critical to their mechanical properties and manufacturing processes for…
We describe measurements demonstrating laser cooling of an atomic gas by means of collisional redistribution of radiation. The experiment uses rubidium atoms in the presence of several hundred bar of argon buffer gas pressure. Frequent…
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…
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…
We used by in-situ high energy X-ray diffraction to inestigate the deformation behavior of Grade 2 commercially pure titanium that was hydrogen charged to form hydrides. The results showed that the peak broadening in the diffraction…
Based on ab initio calculations and metadynamics simulations, we predict that 2H-MoS$_2$, a layered insulator, will metallize under pressures in excess of 20-30 GPa. In the same pressure range, simulations and enthalpy optimization predict…