Ab Initio Simulation of Warm Dense Matter: Combining Density Functional Theory and Linear Response Methods

Kushal Ramakrishna

AutorIn

Kushal Ramakrishna

Titel

Ab Initio Simulation of Warm Dense Matter: Combining Density Functional Theory and Linear Response Methods

Zitierfähige Url:

https://nbn-resolving.org/urn:nbn:de:bsz:14-qucosa2-869371

Erstveröffentlichung

2023

Datum der Einreichung

11.07.2022

Datum der Verteidigung

08.05.2023

Abstract (EN)

Warm dense matter (WDM) is an extreme state of matter induced by extreme conditions and characterized as an intermediary state between (high-pressure) condensed matter and plasma. It has sparked a lot of attention in recent years as a result of current innovations in experiments and theoretical methods for modeling such complex systems. Such conditions naturally occur in astrophysical objects such as the interiors of the planets, and in white and brown dwarfs. WDM can be created in the laboratory via various methods such as laser compression, Z-pinches and heated diamond anvil cells. This thesis describes the results obtained for many such systems across a range of conditions modeled using ab-initio simulation methods. The first testbed concerns the electronic structure and linear response of the carbon phases under high-pressure and warm dense matter conditions. The focus is on modeling inelastic x-ray scattering spectra across a range of conditions useful for the analysis and interpretation of x-ray Thomson scattering (XRTS) experiments. Another major goal is to improve the existing models to compute static properties such as the equation of state, density of states with the inclusion of highly accurate data from quantum Monte Carlo (QMC) simulations relevant at finite-temperatures. This approach improves the accuracy and is also computationally inexpensive compared to path integral Monte Carlo (PIMC) methods. Lastly, improvements in linear response theory relevant for XRTS are incorporated with the inclusion of local field corrections (LFC) and finite-temperature local field corrections (T-LFC) using data from QMC simulations.

Verweis

Ab initio dielectric response function of diamond and other relevant high pressure phases of carbon
DOI: 10.1088/1361-648x/ab558e

Ab initio simulation of warm dense matter
DOI: 10.1063/1.5143225

Influence of finite temperature exchange-correlation effects in hydrogen
DOI: 10.1103/PhysRevB.101.195129

Demonstration of X-ray Thomson scattering as diagnostics for miscibility in warm dense matter
DOI: 10.1038/s41467-020-16426-y

Effective Static Approximation: A Fast and Reliable Tool for Warm-Dense Matter Theory
DOI: 10.1103/PhysRevLett.125.235001

First-principles modeling of plasmons in aluminum under ambient and extreme conditions
DOI: 10.1103/PhysRevB.103.125118

Demonstration of an X-ray Raman Spectroscopy setup to study warm dense carbon at the High Energy Density Instrument of European XFEL
DOI: 10.1063/5.0048150

Dissociating the phononic, magnetic and electronic contributions to thermal conductivity: a computational study in alpha-iron
DOI: 10.1007/s10853-021-06865-3

Electrical conductivity of iron in earth’s core from microscopic Ohm’s Law
DOI: 10.1103/PhysRevB.107.115131

Electronic density response of warm dense matter
DOI: 10.1063/5.0138955

Toward using collective x-ray Thomson scattering to study C–H demixing and hydrogen metallization in warm dense matter conditions
DOI: 10.1063/5.0146416

Freie Schlagwörter (EN)