Finite temperature Green's function approach for excited state and thermodynamic properties of cool to warm dense matter

Abstract

We present a finite-temperature extension of the retarded cumulant Green's function for calculations of exited-state and thermodynamic properties of electronic systems. The method incorporates a cumulant to leading order in the screened Coulomb interaction $W$ and improves excited state properties compared to the $GW$ approximation of many-body perturbation theory. Results for the homogeneous electron gas are presented for a wide range of densities and temperatures, from cool to warm dense matter regime, which reveal several hitherto unexpected properties. For example, correlation effects remain strong at high $T$ while the exchange-correlation energy becomes small. In addition, the spectral function broadens and damping increases with temperature, blurring the usual quasi-particle picture. Similarly Compton scattering exhibits substantial many-body corrections that persist at normal densities and intermediate $T$. Results for exchange-correlation energies and potentials are in good agreement with existing theories and finite-temperature DFT functionals.

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Cited by in corpus (4)

• Ab Initio Path Integral Monte Carlo Approach to the Static and Dynamic Density Response of the Uniform Electron Gas
• Dynamic properties of the warm dense electron gas: an ab initio path integral Monte Carlo approach
• Dynamically screened vertex correction to $GW$
• Nonlinear Density Response and Higher Order Correlation Functions in Warm Dense Matter