197 citations · 2.7k across the 110 of their papers we have counts for
116 papers
The quadratic density response function for non-interacting fermions at arbitrary temperature
Pontus Svensson, Jan Vorberger, Zhandos A. Moldabekov +5
We develop and implement the quadratic density response function of non-interacting fermions at arbitrary temperature, frequencies, and wave vectors. Starting from a Green's functi…
Reconciling chemical models of X-ray Thomson Scattering with the Bethe -sum rule
Maximilian P. Böhme, Paul Hamann, Veronika A. Kruse +9
X-ray Thomson scattering (XRTS) is a key diagnostic for high-energy-density plasmas, which can exhibit significant quantum effects even at elevated temperatures. XRTS experiments a…
Ab initio path integral Monte Carlo study of the 2D uniform electron liquid at finite temperatures
Tobias Dornheim, Fotios Kalkavouras, Paul Hamann +3
We present extensive \emph{ab initio} path integral Monte Carlo (PIMC) simulations of the two-dimensional uniform electron gas (2DEG), covering a broad range of density parameters…
Kinetic energy from the cubic sum rule of the dynamic structure factor
Fotios Kalkavouras, Panagiotis Tolias, Sebastian Schwalbe +6
The third frequency moment sum rule of the dynamic structure factor is explored for the first time as an alternative estimator of the kinetic energy of quantu…
Reweighting Estimators for Density Response in Path Integral Monte Carlo: Applications to linear, nonlinear and cross-species density response
Pontus Svensson, Thomas Chuna, Jan Vorberger +5
We present density response estimators for Monte Carlo simulations that are based on a reweighting procedure, where the samples of an unperturbed system are used to estimate the pr…
Monte-Carlo Event Generation for X-Ray Thomson Scattering Analysis
Uwe Hernandez Acosta, Thomas Gawne, Jan Vorberger +6
A key diagnostic in warm-dense matter (WDM) experiments is X-ray Thomson scattering (XRTS), but its interpretation is often limited by complex instrument effects and the high compu…
Mermin's dielectric function and the f-sum rule
Thomas Chuna, Jan Vorberger, Thomas Gawne +2
Mermin's dielectric function [N.D. Mermin, Phys. Rev. B 1, 2362 (1970)] is widely assumed to satisfy the f-sum rule because he constrains his ansatz with the continuity equation. H…
Unlocking the Power of Orbital-Free Density Functional Theory to Explore the Electronic Structure Under Extreme Conditions
Cheng Ma, Qiang Xu, Zhenhao Zhang +8
Recent advances in X-ray free-electron laser diagnostics have enabled direct probing of the electronic structure under extreme pressures and temperatures, such as those encountered…
Ab initio path-integral Monte Carlo results for the one-particle spectral function of the warm dense electron gas
Paul Hamann, Michael Bonitz, Jan Vorberger +1
We present quasi-exact \emph{ab initio} path-integral Monte Carlo results for the Matsubara Green's function of the uniform electron gas (UEG) at finite temperature over a broad ra…
Generalized density functional theory framework for the non-linear density response of quantum many-body systems
Zhandos A. Moldabekov, Cheng Ma, Xuecheng Shao +5
A density functional theory (DFT) framework is presented that links functional derivatives of free-energy functionals to non-linear static density response functions in quantum man…
Van-der-Waals exchange-correlation functionals and their high pressure and warm dense matter applications
Jan Vorberger, Gabriel J. Smith, William Z. Van Benschoten +4
We investigate basic hydrogen quantities like the molecular bond length, the molecular dissociation energy and the van-der-Waals interaction in idealized situations in an effort to…
Spectral Deconvolution without the Deconvolution: Extracting Temperature from X-ray Thomson Scattering Spectra without the Source-and-Instrument Function
Thomas Gawne, Alina Kononov, Andrew Baczewski +7
X-ray Thomson scattering (XRTS) probes the dynamic structure factor of the system, but the measured spectrum is broadened by the combined source-and-instrument function (SIF) of th…
Enhancing the Efficiency of Time-Dependent Density Functional Theory Calculations of Dynamic Response Properties
Zhandos A. Moldabekov, Sebastian Schwalbe, Uwe Hernandez Acosta +4
X-ray Thomson scattering (XRTS) constitutes an essential technique for diagnosing material properties under extreme conditions, such as high pressures and intense laser heating. Ti…
Correlation function metrology for warm dense matter: Recent developments and practical guidelines
Maximilian Peter Böhme, Willow Martin, Hannah Bellenbaum +13
X-ray Thomson scattering (XRTS) has emerged as a valuable diagnostic for matter under extreme conditions, as it captures the intricate many-body physics of the probed sample. Recen…
Taylor series perspective on ab initio path integral Monte Carlo simulations with Fermi-Dirac statistics
Tobias Dornheim, Alexander Benedix Robles, Paul Hamann +6
The fermion sign problem constitutes a fundamental computational bottleneck across a plethora of research fields in physics, quantum chemistry and related disciplines. Recently, it…
Reweighting scheme for the calculation of grand-canonical expectation values in quantum Monte Carlo simulations with a fermion sign problem
Paul Hamann, Jan Vorberger, Tobias Dornheim
Ab initio path integral Monte Carlo (PIMC) simulations constitute the gold standard for the estimation of a broad range of equilibrium properties of a host of interacting quantum m…
Kinetic contribution to the arbitrary order odd frequency moments of the dynamic structure factor
Panagiotis Tolias, Tobias Dornheim, Jan Vorberger
An exact expression is derived for the kinetic contribution to the odd (arbitrary order) frequency moments of the dynamic structure factor via a finite summation that features aver…
Re-weighting estimator for ab initio path integral Monte Carlo simulations of fictitious identical particles
Tobias Dornheim, Pontus Svensson, Paul Hamann +4
The fermion sign problem constitutes one of the most fundamental obstacles in quantum many-body theory. Recently, it has been suggested to circumvent the sign problem by carrying o…
Orientational Effects in the Low Pair Continuum of Aluminium
Thomas Gawne, Zhandos A Moldabekov, Oliver S Humphries +6
We compare the predictions of the dynamic structure factor (DSF) of ambient polycrystalline aluminium from time-dependent density functional theory (TDDFT) in the pair continuum re…
Accelerated free energy estimation in ab initio path integral Monte Carlo simulations
Pontus Svensson, Fotios Kalkavouras, Uwe Hernandez Acosta +4
We present a methodology for accelerating the estimation of the free energy from path integral Monte Carlo simulations by considering an intermediate artificial reference system wh…
Ab initio density functional theory approach to warm dense hydrogen: from density response to electronic correlations
Zhandos A. Moldabekov, Xuecheng Shao, Hannah M. Bellenbaum +5
Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confineme…
Exact series expansion for even frequency moments of the dynamic structure factor
Panagiotis Tolias, Jan Vorberger, Tobias Dornheim
An exact series representation of the even frequency moments of the dynamic structure factor is derived. Truncations are proposed that allow to evaluate the explicitly unknown seco…
Second roton feature in the strongly coupled electron liquid
Thomas M. Chuna, Jan Vorberger, Panagiotis Tolias +5
We present extensive \emph{ab initio} path integral Monte Carlo (PIMC) results for the dynamic properties of the finite temperature uniform electron gas (UEG) over a broad range of…
Roadmap for warm dense matter physics
Jan Vorberger, Frank Graziani, David Riley +71
This roadmap presents the state-of-the-art, current challenges and near future developments anticipated in the thriving field of warm dense matter physics. Originating from strongl…