Optical Properties and One‐Particle Spectral Function in Non‐Ideal Plasmas

Abstract

A basic concept to calculate physical features of non-ideal plasmas, such as optical properties, is the spectral function which is linked to the self-energy. We calculate the spectral function for a non-relativistic hydrogen plasma in GW -approximation. In order to go beyond GW approximation, we include self-energy and vertex correction to the polarization function in lowest order. Partial compensation is observed. The relation of our approach to GW and GW Γ calculations in other fields, such as the band-structure calculations in semiconductor physics, is discussed. From the spectral function we derive the absorption coefficient due to inverse bremsstrahlung via the polarization function. As a result, a significant reduction of the absorption as compared to the Bethe-Heitler formula for bremsstrahlung is obtained.

Self-consistent spectral function for non-degenerate Coulomb systems and analytic scaling behaviour

“…A typical example of a weakly coupled ( = 0.07), moderately degenerate (θ = 2.2) plasma is the plasma at the solar core, with temperatures of T 100 Ry/k B 1360 eV/k B and electron densities of n 7×10 25 cm −3 [49]. The solar core plasma has been investigated using the GW (0) -method in a number of previous publications, see [18,37,50]. Here, most attention is paid to a systematic analysis of the single-particle spectral function and the self-energy over a broad range of densities and temperatures, however, sticking to nondegenerate plasmas and neglecting bound states.…”

“…The equation of state [15], transport cross-sections [16] (e.g. electrical conductivity, thermal conductivity and stopping power [17]) and optical properties [18] (emission and absorption of electromagnetic radiation) become accessible.…”

Single-particle spectral function for the classical one-component plasma

“…Green functions know a long history of applications in solid state theory [2], nuclear [3], and hadron physics [4], and also in the theory of strongly coupled plasmas [5]. In the latter case, optical and dielectric properties [6,7] have been studied using the Green function approach, as well as transport properties like conductivity [8] and stopping power [9,10], and the equation of state [11]. Modifications of these quantities due to the interaction among the constituents can be accessed, starting from a common starting point, namely the Hamiltonian of the system.…”

“…Throughout this work, the GW (0) self-energy will be analyzed.Having been used in solid state physics traditionally, the GW (0) -method was also applied to study correlations in hot and dense plasmas, recently. The equation of state [31,32], as well as optical properties of electron hole plasmas in highly excited semiconductors [33], and dense hydrogen plasmas [7] were investigated.In general, the calculation of such macroscopic observables of many-particle system involves numerical operations that need the spectral function as an input. Since the self-consistent calculation of the self-energy, even in GW (0)approximation, is itself already a numerically demanding task, it is worth looking for an analytic solution of the GW (0) equations, which reproduces the numerical solution at least in a certain range of plasma parameters.…”

“…Having been used in solid state physics traditionally, the GW (0) -method was also applied to study correlations in hot and dense plasmas, recently. The equation of state [31,32], as well as optical properties of electron hole plasmas in highly excited semiconductors [33], and dense hydrogen plasmas [7] were investigated.…”