Perturbation Theory by Flow Equations: Dimerized and Frustrated S=1/2 Chain

Preprint

16 June 1999

preprint
Published by arXiv in arXiv

https://doi.org/10.48550/arXiv.cond-mat/9906243

Abstract

The flow equation method (Wegner 1994) is used as continuous unitary transformation to construct perturbatively effective Hamiltonians. The method is illustrated in detail for dimerized and frustrated antiferromagnetic S=1/2 chains. The effective Hamiltonians conserve the number of elementary excitations which are S=1 magnons for the dimerized chains. The sectors of different number of excitations are clearly separated. Easy-to-use results for the gap, the dispersion and the ground state energies of the chains are provided.

Keywords

DIMERIZED AND FRUSTRATED
EFFECTIVE HAMILTONIANS
PERTURBATION THEORY
ANTIFERROMAGNETIC
EQUATION METHOD
FLOW EQUATIONS
HAMILTONIANS
FRUSTRATED
WEGNER

All Related Versions

Version 1, 1999-06-16, ArXiv
Published version: Zeitschrift für Physik B Condensed Matter, 13 (2), 209.

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