EFFICIENT CALCULATION OF HIGH-ORDER SELF-ENERGY CORRECTIONS TO PHONONLINEWIDTHS - APPLICATION TO ALPHA-NITROGEN

Citation
P. Procacci et al., EFFICIENT CALCULATION OF HIGH-ORDER SELF-ENERGY CORRECTIONS TO PHONONLINEWIDTHS - APPLICATION TO ALPHA-NITROGEN, Physical review. B, Condensed matter, 47(17), 1993, pp. 11124-11133
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Condensed Matter
ISSN journal
0163-1829
Volume
47
Issue
17
Year of publication
1993
Pages
11124 - 11133
Database
ISI
SICI code
0163-1829(1993)47:17<11124:ECOHSC>2.0.ZU;2-4
Abstract
This paper presents an efficient method for computing high-order corre ctions to phonon linewidths in crystals. Traditional algorithms involv e nested sums over intermediate phonon states, whose computational tim e grows exponentially with the perturbation order. This nested-sum dif ficulty is overcome in the present study for the special case of the d ouble-vertex diagrams by writing the corresponding linewidths in a sim ple form and exploiting a recursive algorithm for weighted phonon dens ities of states, which requires a time linear in the perturbation orde r. Using this method, we computed, up to order 10, the linewidths due to the double-vertex diagrams for the a-nitrogen crystal. Our calculat ion shows that accurate estimates of high-order linewidth corrections can be obtained even for systems as complex as molecular crystals.