100 citations · 684 across the 58 of their papers we have counts for
61 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…
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…
Dielectric formalism of the 2D uniform electron gas at finite temperatures
Fotios Kalkavouras, Tobias Dornheim, Paul Hamann +1
We present a comprehensive analysis of the two-dimensional uniform electron gas (2D-UEG or more commonly 2DEG) at finite temperature, spanning a broad range of densities / coupling…
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…
Thermal resilience of the ITER tungsten first wall to runaway electron impact
S. Ratynskaia, K. Paschalidis, T. Rizzi +7
The fast volumetric deposition of multi-MeV high current runaway electron (RE) beams constitutes the most critical issue for the ITER tungsten (W) first wall (FW) longevity. Such r…
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…
Wall damage due to oblique high velocity dust impacts
Panagiotis Tolias, Marco De Angeli, Dario Ripamonti +3
Runaway electron termination on plasma facing components can trigger material explosions that are accompanied by the expulsion of fast solid debris. Due to the large kinetic energi…
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…
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…
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…
Static linear density response from X-ray Thomson scattering measurements: a case study of warm dense beryllium
Sebastian Schwalbe, Hannah Bellenbaum, Tilo Döppner +8
Linear response theory is ubiquitous throughout physics and plays a central role in the theoretical description of warm dense matter -- an extreme state that occurs within compact…
Application of a spherically averaged pair potential in \emph{ab initio} path integral Monte Carlo simulations of the warm dense electron gas
Tobias Dornheim, Thomas M. Chuna, Hannah M. Bellenbaum +3
Spherically averaged periodic pair potentials offer the enticing promise to provide accurate results at a drastically reduced computational cost compared to the traditional Ewald s…
Fermionic free energies from \textit{ab initio} path integral Monte Carlo simulations of fictitious identical particles
Tobias Dornheim, Zhandos Moldabekov, Sebastian Schwalbe +2
We combine the recent ensemble path integral Monte Carlo (PIMC) approach to the free energy [T.~Dornheim \textit{et al.}, \textit{Phys.~Rev.~B} \textbf{111}, L041114 (2025)] wi…
Chemical potential of the warm dense electron gas from ab initio path integral Monte Carlo simulations
Tobias Dornheim, Michael Bonitz, Zhandos Moldabekov +3
We present extensive new \emph{ab initio} path integral Monte Carlo (PIMC) simulation results for the chemical potential of the warm dense uniform electron gas (UEG), spanning a br…
η-ensemble path integral Monte Carlo approach to the free energy of the warm dense electron gas and the uniform electron liquid
Tobias Dornheim, Panagiotis Tolias, Zhandos Moldabekov +1
We explore the recently introduced -ensemble approach to compute the free energy directly from \emph{ab initio} path integral Monte Carlo (PIMC) simulations [T.~Dornheim \emph{e…
Dynamic properties of the warm dense uniform electron gas with the qSTLS dielectric scheme
Panagiotis Tolias, Fotios Kalkavouras, Tobias Dornheim +1
The recently derived Fourier--Matsubara expansion of imaginary--time correlation functions comprises an exact result of linear response theory for finite-temperature quantum many-b…
On the density-density correlations of the non-interacting finite temperature electron gas
Panagiotis Tolias, Tobias Dornheim, Jan Vorberger
The density-density correlations of the non-interacting finite temperature electron gas are discussed in detail. Starting from the ideal linear density response function and utiliz…
Green's function perspective on the nonlinear density response of quantum many-body systems
Jan Vorberger, Tobias Dornheim, Maximilian P. Böhme +2
We derive equations of motion for higher order density response functions using the theory of thermodynamic Green's functions. We also derive expressions for the higher order gener…
Model-free Rayleigh weight from x-ray Thomson scattering measurements
Tobias Dornheim, Hannah M. Bellenbaum, Mandy Bethkenhagen +16
X-ray Thomson scattering (XRTS) has emerged as a powerful tool for the diagnostics of matter under extreme conditions. In principle, it gives one access to important system paramet…