Warm dense matter
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Linac Coherent Light Source: The first five years Open
A new scientific frontier opened in 2009 with the start of operations of the world's first x-ray free-electron laser (FEL), the Linac Coherent Light Source (LCLS), at SLAC National Accelerator Laboratory. LCLS provides femtosecond pulses o…
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<i>Ab initio</i> Exchange-Correlation Free Energy of the Uniform Electron Gas at Warm Dense Matter Conditions Open
In a recent Letter [T. Dornheim et al., Phys. Rev. Lett. 117, 156403 (2016)PRLTAO0031-900710.1103/PhysRevLett.117.156403], we presented the first quantum Monte Carlo (QMC) results for the warm dense electron gas in the thermodynamic limit.…
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P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines Open
ELI-Beamlines (ELI-BL), one of the three pillars of the Extreme Light Infrastructure endeavour, will be in a unique position to perform research in high-energy-density-physics (HEDP), plasma physics and ultra-high intensity (UHI) (1022W/cm…
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Accurate Semilocal Density Functional for Condensed-Matter Physics and Quantum Chemistry Open
Most density functionals have been developed by imposing the known exact constraints on the exchange-correlation energy, or by a fit to a set of properties of selected systems, or by both. However, accurate modeling of the conventional exc…
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Importance of finite-temperature exchange correlation for warm dense matter calculations Open
The effects of an explicit temperature dependence in the exchange correlation (XC) free-energy functional upon calculated properties of matter in the warm dense regime are investigated. The comparison is between the Karasiev-Sjostrom-Dufty…
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<i>Ab Initio</i>Thermodynamic Results for the Degenerate Electron Gas at Finite Temperature Open
The uniform electron gas at finite temperature is of key relevance for many applications in dense plasmas, warm dense matter, laser excited solids, and much more. Accurate thermodynamic data for the uniform electron gas are an essential in…
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<i>Ab initio</i> Path Integral Monte Carlo Results for the Dynamic Structure Factor of Correlated Electrons: From the Electron Liquid to Warm Dense Matter Open
The accurate description of electrons at extreme density and temperature is of paramount importance for, e.g., the understanding of astrophysical objects and inertial confinement fusion. In this context, the dynamic structure factor S(q,ω)…
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Free-Electron X-Ray Laser Measurements of Collisional-Damped Plasmons in Isochorically Heated Warm Dense Matter Open
We present the first highly resolved measurements of the plasmon spectrum in an ultrafast heated solid. Multi-keV x-ray photons from the Linac Coherent Light Source have been focused to one micrometer diameter focal spots producing solid d…
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Matter under extreme conditions experiments at the Linac Coherent Light Source Open
The Matter in Extreme Conditions end station at the Linac Coherent Light Source (LCLS) is a new tool enabling accurate pump-probe measurements for studying the physical properties of matter in the high-energy density physics regime. This i…
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Measurement of Charged-Particle Stopping in Warm Dense Plasma Open
We measured the stopping of energetic protons in an isochorically heated solid-density Be plasma with an electron temperature of ∼32 eV, corresponding to moderately coupled [(e^{2}/a)/(k_{B}T_{e}+E_{F})∼0.3] and moderately degenerate [k_{B…
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Fermion sign problem in path integral Monte Carlo simulations: Quantum dots, ultracold atoms, and warm dense matter Open
The ab initio thermodynamic simulation of correlated Fermi systems is of central importance for many applications, such as warm dense matter, electrons in quantum dots, and ultracold atoms. Unfortunately, path integral Monte Carlo (PIMC) s…
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Experimental methods for warm dense matter research Open
The study of structure, thermodynamic state, equation of state (EOS) and transport properties of warm dense matter (WDM) has become one of the key aspects of laboratory astrophysics. This field has demonstrated its importance not only conc…
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X-ray Thomson Scattering in Warm Dense Matter without the Chihara Decomposition Open
X-ray Thomson scattering is an important experimental technique used to measure the temperature, ionization state, structure, and density of warm dense matter (WDM). The fundamental property probed in these experiments is the electronic dy…
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Nonempirical Semilocal Free-Energy Density Functional for Matter under Extreme Conditions Open
Realizing the potential for predictive density functional calculations of matter under extreme conditions depends crucially upon having an exchange-correlation (XC) free-energy functional accurate over a wide range of state conditions. Unl…
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The static local field correction of the warm dense electron gas: An <i>ab initio</i> path integral Monte Carlo study and machine learning representation Open
The study of matter at extreme densities and temperatures as they occur in astrophysical objects and state-of-the-art experiments with high-intensity lasers is of high current interest for many applications. While no overarching theory for…
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Development of Path Integral Monte Carlo Simulations with Localized Nodal Surfaces for Second-Row Elements Open
We extend the applicability range of fermionic path integral Monte Carlo simulations to heavier elements and lower temperatures by introducing various localized nodal surfaces. Hartree-Fock nodes yield the most accurate prediction for pres…
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Warm Dense Matter Demonstrating Non-Drude Conductivity from Observations of Nonlinear Plasmon Damping Open
We present simulations using finite-temperature density-functional-theory molecular dynamics to calculate the dynamic electrical conductivity in warm dense aluminum. The comparison between exchange-correlation functionals in the Perdew-Bur…
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Characterizing the ionization potential depression in dense carbon plasmas with high-precision spectrally resolved x-ray scattering Open
We discuss here the possibility of obtaining highly precise measurements of the ionization potential depression in dense plasmas with spectrally resolved x-ray scattering, while simultaneously determining the electron temperature and the f…
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Effective Static Approximation: A Fast and Reliable Tool for Warm-Dense Matter Theory Open
We present an effective static approximation (ESA) to the local field correction (LFC) of the electron gas that enables highly accurate calculations of electronic properties like the dynamic structure factor S(q,ω), the static structure fa…
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<i>Ab initio</i> path integral Monte Carlo approach to the static and dynamic density response of the uniform electron gas Open
In a recent Letter [T. Dornheim et al., Phys. Rev. Lett. 121, 255001 (2018)]\nwe have presented the first ab initio results for the dynamic structure factor\n$S(\\mathbf{q},\\omega)$ of the uniform electron gas for conditions ranging from\…
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Measurement of Electron-Ion Relaxation in Warm Dense Copper Open
Experimental investigation of electron-ion coupling and electron heat capacity of copper in warm and dense states are presented. From time-resolved x-ray absorption spectroscopy, the temporal evolution of electron temperature is obtained f…
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Nonlinear Electronic Density Response in Warm Dense Matter Open
This repository contains the PIMC raw data for the actual density response of the harmonically perturbed electron gas. The data can be freely re-used. Please cite: T. Dornheim, J. Vorberger, and M. Bonitz, Nonlinear Electronic Density Resp…
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Electronic density response of warm dense matter Open
Matter at extreme temperatures and pressures—commonly known as warm dense matter (WDM)—is ubiquitous throughout our Universe and occurs in astrophysical objects such as giant planet interiors and brown dwarfs. Moreover, WDM is very importa…
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<i>Ab initio</i>quantum Monte Carlo simulations of the uniform electron gas without fixed nodes Open
The uniform electron gas (UEG) at finite temperature is of key relevance for many applications in the warm dense matter regime, e.g. dense plasmas and laser excited solids. Also, the quality of density functional theory calculations crucia…
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<i>Ab initio</i> quantum Monte Carlo simulation of the warm dense electron gas Open
Warm dense matter is one of the most active frontiers in plasma physics due to its relevance for dense astrophysical objects and for novel laboratory experiments in which matter is being strongly compressed, e.g., by high-power lasers. Its…
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Pasta nucleosynthesis: Molecular dynamics simulations of nuclear statistical equilibrium Open
Background: Exotic non-spherical nuclear pasta shapes are expected in nuclear matter at just below saturation density because of competition between short range nuclear attraction and long range Coulomb repulsion. Purpose: We explore the i…
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First-principles equation of state calculations of warm dense nitrogen Open
Using path integral Monte Carlo (PIMC) and density functional molecular dynamics (DFT-MD) simulation methods, we compute a coherent equation of state (EOS) of nitrogen that spans the liquid, warm dense matter (WDM), and plasma regimes. Sim…
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Influence of finite temperature exchange-correlation effects in hydrogen Open
We use density functional molecular dynamics (DFT-MD) to study the effect of finite temperature exchange-correlation (xc) in Hydrogen. Using the Kohn-Sham approach, the xc energy of the system, $E_{xc}(r_{s})$ is replaced by the xc free en…
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Path integral Monte Carlo simulations of warm dense aluminum Open
We perform first-principles path integral Monte Carlo (PIMC) and density functional theory molecular dynamics (DFT-MD) calculations to explore warm dense matter states of aluminum. Our equation of state (EOS) simulations cover a wide densi…
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Electrical conductivity of a warm neutron star crust in magnetic fields Open
We study the electrical conductivity of finite-temperature crust of a warm compact star which may be formed in the aftermath of a supernova explosion or a binary neutron star merger as well as when a cold neutron star is heated by accretio…