Optical potentials and damped oneelectron functions in photoemission and electron scattering
(1990) In Journal of Electron Spectroscopy and Related Phenomena 51. p.91102 Abstract
 Recently a new approach to photoemission, EXAFS and electron scattering has been developed. The correlations between target electrons are separated from the active electrontarget electron correlations, and the damping effects are coming out explicitly. The theory uses van Hove diagonal Green's functions and projection operator techniques, not the usual diagram expansions. By omitting from the start terms in the Hamiltonian which lead to reabsorption of the active electron (photoelectron or scattered electron), remarkably simple expressions are obtained. These expressions contain optical potentials which damp the electron propagation, and “fluctuation potentials” which determine the inelastic scattering. The fluctuation potentials also... (More)
 Recently a new approach to photoemission, EXAFS and electron scattering has been developed. The correlations between target electrons are separated from the active electrontarget electron correlations, and the damping effects are coming out explicitly. The theory uses van Hove diagonal Green's functions and projection operator techniques, not the usual diagram expansions. By omitting from the start terms in the Hamiltonian which lead to reabsorption of the active electron (photoelectron or scattered electron), remarkably simple expressions are obtained. These expressions contain optical potentials which damp the electron propagation, and “fluctuation potentials” which determine the inelastic scattering. The fluctuation potentials also appear in the expressions for the optical potentials. On the RPA level of approximation the fluctuation potentials are obtained from the dielectric response function of the target. The theory is quite general, but its main advantages are for extended systems, where the damped propagators and damped one electron functions are important effects. The present theory should make it possible to quantitatively attack a number of correlation effects in different spectroscopies. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/8821021
 author
 Hedin, Lars ^{LU}
 organization
 publishing date
 1990
 type
 Contribution to journal
 publication status
 published
 subject
 in
 Journal of Electron Spectroscopy and Related Phenomena
 volume
 51
 pages
 91  102
 publisher
 Elsevier
 external identifiers

 scopus:0345249054
 ISSN
 03682048
 DOI
 10.1016/03682048(90)80144Y
 language
 English
 LU publication?
 yes
 id
 79d7024a909b454586d0c283a92aacc6 (old id 8821021)
 date added to LUP
 20160301 09:40:49
 date last changed
 20180529 11:07:24
@article{79d7024a909b454586d0c283a92aacc6, abstract = {Recently a new approach to photoemission, EXAFS and electron scattering has been developed. The correlations between target electrons are separated from the active electrontarget electron correlations, and the damping effects are coming out explicitly. The theory uses van Hove diagonal Green's functions and projection operator techniques, not the usual diagram expansions. By omitting from the start terms in the Hamiltonian which lead to reabsorption of the active electron (photoelectron or scattered electron), remarkably simple expressions are obtained. These expressions contain optical potentials which damp the electron propagation, and “fluctuation potentials” which determine the inelastic scattering. The fluctuation potentials also appear in the expressions for the optical potentials. On the RPA level of approximation the fluctuation potentials are obtained from the dielectric response function of the target. The theory is quite general, but its main advantages are for extended systems, where the damped propagators and damped one electron functions are important effects. The present theory should make it possible to quantitatively attack a number of correlation effects in different spectroscopies.}, author = {Hedin, Lars}, issn = {03682048}, language = {eng}, pages = {91102}, publisher = {Elsevier}, series = {Journal of Electron Spectroscopy and Related Phenomena}, title = {Optical potentials and damped oneelectron functions in photoemission and electron scattering}, url = {http://dx.doi.org/10.1016/03682048(90)80144Y}, volume = {51}, year = {1990}, }