Bond-impurity induced bound states in disordered spin-1/2 ladders

We discuss the effect of weak bond-disorder in two-leg spin ladders on the dispersion relation of the elementary triplet excitations with a particular focus on the appearance of bound states in the spin gap. Both the cases of modified exchange couplings on the rungs and the legs of the ladder are an...

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Detalles Bibliográficos
Autores principales: Arlego, Marcelo José Fabián, Brenig, Wolfram, Cabra, Daniel Carlos, Heidrich-Meisner, Fabian, Honecker, Andreas, Rossini, Gerardo Luis
Formato: Articulo
Lenguaje:Inglés
Publicado: 2004
Materias:
Física
Coupling
Physics
Cluster (physics)
Projection (linear algebra)
Bound state
Dispersion relation
Condensed matter physics
Spectral line
Density of states
Quantum mechanics
Spin-½
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/126328
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-126328
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Física
Coupling
Physics
Cluster (physics)
Projection (linear algebra)
Bound state
Dispersion relation
Condensed matter physics
Spectral line
Density of states
Quantum mechanics
Spin-½
spellingShingle Física
Coupling
Physics
Cluster (physics)
Projection (linear algebra)
Bound state
Dispersion relation
Condensed matter physics
Spectral line
Density of states
Quantum mechanics
Spin-½
Arlego, Marcelo José Fabián
Brenig, Wolfram
Cabra, Daniel Carlos
Heidrich-Meisner, Fabian
Honecker, Andreas
Rossini, Gerardo Luis
Bond-impurity induced bound states in disordered spin-1/2 ladders
topic_facet Física
Coupling
Physics
Cluster (physics)
Projection (linear algebra)
Bound state
Dispersion relation
Condensed matter physics
Spectral line
Density of states
Quantum mechanics
Spin-½
description We discuss the effect of weak bond-disorder in two-leg spin ladders on the dispersion relation of the elementary triplet excitations with a particular focus on the appearance of bound states in the spin gap. Both the cases of modified exchange couplings on the rungs and the legs of the ladder are analyzed. Based on a projection on the single-triplet subspace, the single-impurity and small cluster problems are treated analytically in the strong-coupling limit. Numerically, we study the problem of a single impurity in a spin ladder by exact diagonalization to obtain the low-lying excitations. At finite concentrations and to leading order in the inter-rung coupling, we compare the spectra obtained from numerical diagonalization of large systems within the single-triplet subspace with the results of diagrammatic techniques, namely low-concentration and coherent-potential approximations. The contribution of small impurity clusters to the density of states is also discussed.
format Articulo
Articulo
author Arlego, Marcelo José Fabián
Brenig, Wolfram
Cabra, Daniel Carlos
Heidrich-Meisner, Fabian
Honecker, Andreas
Rossini, Gerardo Luis
author_facet Arlego, Marcelo José Fabián
Brenig, Wolfram
Cabra, Daniel Carlos
Heidrich-Meisner, Fabian
Honecker, Andreas
Rossini, Gerardo Luis
author_sort Arlego, Marcelo José Fabián
title Bond-impurity induced bound states in disordered spin-1/2 ladders
title_short Bond-impurity induced bound states in disordered spin-1/2 ladders
title_full Bond-impurity induced bound states in disordered spin-1/2 ladders
title_fullStr Bond-impurity induced bound states in disordered spin-1/2 ladders
title_full_unstemmed Bond-impurity induced bound states in disordered spin-1/2 ladders
title_sort bond-impurity induced bound states in disordered spin-1/2 ladders
publishDate 2004
url http://sedici.unlp.edu.ar/handle/10915/126328
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AT cabradanielcarlos bondimpurityinducedboundstatesindisorderedspin12ladders
AT heidrichmeisnerfabian bondimpurityinducedboundstatesindisorderedspin12ladders
AT honeckerandreas bondimpurityinducedboundstatesindisorderedspin12ladders
AT rossinigerardoluis bondimpurityinducedboundstatesindisorderedspin12ladders
bdutipo_str Repositorios
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