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Importance of vertex corrections for obtaining correct selection rules in the theory of photoemission

Almbladh, Carl-Olof LU (1986) In Physical Review B 34(6). p.3798-3806
Abstract
It is shown that the commonly used approximation for the no-loss angle-resolved photocurrent from solids in general violates the optical selection rules if the final-state inverse low-energy electron diffraction orbital is taken to be damped. The violations occur in the velocity formula, which is inconsistent with the corresponding and commonly used acceleration formula in which the matrix elements are evaluated with respect to the gradient of the one-electron potential. It has recently been shown that, in a correct description of the no-loss photocurrent, the bare matrix elements should be replaced by the appropriate vector-coupling vertex function. We demonstrate that this modification is needed in order to have correct selection rules... (More)
It is shown that the commonly used approximation for the no-loss angle-resolved photocurrent from solids in general violates the optical selection rules if the final-state inverse low-energy electron diffraction orbital is taken to be damped. The violations occur in the velocity formula, which is inconsistent with the corresponding and commonly used acceleration formula in which the matrix elements are evaluated with respect to the gradient of the one-electron potential. It has recently been shown that, in a correct description of the no-loss photocurrent, the bare matrix elements should be replaced by the appropriate vector-coupling vertex function. We demonstrate that this modification is needed in order to have correct selection rules and consistency between the velocity and acceleration formulas for photoemission and photoabsorption. Our formalism further allows us to interpret the commonly used acceleration formula in terms of a well-defined approximation which leaves out local-field effects, and to give approximations which obey the selection rules. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
34
issue
6
pages
3798 - 3806
publisher
American Physical Society
external identifiers
  • Scopus:26344449409
ISSN
1550-235X
language
English
LU publication?
yes
id
e119283a-5a1e-4d37-b7c6-1a66c9182c5a (old id 8773866)
date added to LUP
2016-02-27 01:06:21
date last changed
2016-10-13 05:00:13
@misc{e119283a-5a1e-4d37-b7c6-1a66c9182c5a,
  abstract     = {It is shown that the commonly used approximation for the no-loss angle-resolved photocurrent from solids in general violates the optical selection rules if the final-state inverse low-energy electron diffraction orbital is taken to be damped. The violations occur in the velocity formula, which is inconsistent with the corresponding and commonly used acceleration formula in which the matrix elements are evaluated with respect to the gradient of the one-electron potential. It has recently been shown that, in a correct description of the no-loss photocurrent, the bare matrix elements should be replaced by the appropriate vector-coupling vertex function. We demonstrate that this modification is needed in order to have correct selection rules and consistency between the velocity and acceleration formulas for photoemission and photoabsorption. Our formalism further allows us to interpret the commonly used acceleration formula in terms of a well-defined approximation which leaves out local-field effects, and to give approximations which obey the selection rules.},
  author       = {Almbladh, Carl-Olof},
  issn         = {1550-235X},
  language     = {eng},
  number       = {6},
  pages        = {3798--3806},
  publisher    = {ARRAY(0x8eb7ea8)},
  series       = {Physical Review B},
  title        = {Importance of vertex corrections for obtaining correct selection rules in the theory of photoemission},
  volume       = {34},
  year         = {1986},
}