The truncation of the Mori continued fraction for the spectral function in Heisenberg and XY models

M. Drawid, J. W. Halley

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

We study the truncation of the Mori continued fraction for the two-spin spectral function of the XY model in various schemes suggested by the 3-pole approximation. These schemes are (i) a fully consistent version of the 3-pole approximation; (ii) 5-pole approximation (not fully consistent); and (iii) 5-pole approximate (fully consistent). We establish the equilivalence between the fully consistent 3-pole approximation and the Bennett-Martin approximation. Finally, we calculate the time-dependent spin-spin correlation function for the classical Heisenberg model in both versions of the 3-pole approximation and compare it with the exact spin-spin correlation function obtained by direct numerical calculation in one dimension.

Original languageEnglish (US)
Pages (from-to)1269-1274
Number of pages6
JournalJournal of Physics and Chemistry of Solids
Volume38
Issue number11
DOIs
StatePublished - 1977
Externally publishedYes

Fingerprint Dive into the research topics of 'The truncation of the Mori continued fraction for the spectral function in Heisenberg and XY models'. Together they form a unique fingerprint.

Cite this