Generalized time-dependent density-functional-theory response functions for spontaneous density fluctuations and nonlinear response: Resolving the causality paradox in real time

Journal Article · Tue Feb 01 04:00:00 EST 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.024503· OSTI ID:20650142

Mukamel, Shaul ^[1]

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1. Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

Time-ordered superoperators are used to develop a unified description of nonlinear density response and spontaneous fluctuations of many-electron systems. The pth-order density response functions are decomposed into 2{sup p+1} non-causal Liouville space pathways. Individual pathways are symmetric to the interchange of their space, time, and superoperator indices and can thus be calculated as functional derivatives. Other combinations of these pathways represent spontaneous density fluctuations and the response of such fluctuations to an external field. The resolution of the causality paradox of time-dependent density-functional theory (TDDFT) is shown to be intimately connected with the nonretarded nature of fluctuations.

• OSTI ID: 20650142
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 71; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
CAUSALITY
DENSITY
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
ELECTRONS
FLUCTUATIONS
NONLINEAR PROBLEMS
RESOLUTION
RESPONSE FUNCTIONS
SPACE
SUPEROPERATORS
TIME DEPENDENCE