Open AccessXAFS theory studied by closed‐path Green's function
Author(s) -
Fujikawa Takashi
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049500018495
Subject(s) - x ray absorption fine structure , function (biology) , green's function , scattering , path (computing) , resonance (particle physics) , absorption (acoustics) , physics , quantum mechanics , optics , spectroscopy , computer science , evolutionary biology , biology , programming language
The basic framework of X‐ray absorption fine structure (XAFS) theory is formulated by use of the non‐equilibrium Keldysh–Green function, which presents a unified view of XAFS spectra at zero and nonzero temperature. In particular, the relation between the scattering Green's function and the retarded Green's function G r is discussed, along with resonance effects in XAFS. The latter effects give rise to unexpected peaks within one‐electron theory. Loss effects, both intrinsic and extrinsic, are also discussed.