Electronic excitations and correlation effects in metals

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:634117

Eguiluz, A G; Schoene, W D ^[1]

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1. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics

Theoretical descriptions of the spectrum of electronic excitations in real metals have not yet reached a fully predictive, first-principles stage. In this paper the authors begin by presenting brief highlights of recent progress made in the evaluation of dynamical electronic response in metals. A comparison between calculated and measured spectra--they use the loss spectra of Al and Cs as test cases--leads them to the conclusion that, even in weakly-correlated metals, correlation effects beyond mean-field theory play an important role. Furthermore, the effects of the underlying band structure turn out to be significant. Calculations which incorporate the effects of both dynamical correlations and band structure from first principles are not yet available. As a first step towards such goal, they outline a numerical algorithm for the self-consistent solution of the Dyson equation for the one-particle Green`s function. The self-energy is evaluated within the shielded-interaction approximation of Baym and Kadanoff. Their method, which is fully conserving, is a finite-temperature scheme which determines the Green`s function and the self-energy at the Matsubara frequencies on the imaginary axis. The analytical continuation to real frequencies is performed via Pade` approximant. They present results for the homogeneous electron gas which exemplify the importance of many-body self-consistency.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 634117
• Report Number(s): CONF-9706178--1; ON: DE97008547; CNN: Grant DMR-9634502
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALGORITHMS
ALUMINIUM
BAND THEORY
CESIUM
CORRELATIONS
ELECTRON GAS
MANY-BODY PROBLEM
MEAN-FIELD THEORY
METALS
SELF-CONSISTENT FIELD