Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/73356
Título: | Bethe strings in the dynamical structure factor of the spin-1/2 Heisenberg XXX chain |
Autor(es): | Carmelo, José Manuel Pereira Čadež, Tilen Sacramento, Pedro D. |
Data: | 2020 |
Editora: | Elsevier 1 |
Revista: | Nuclear Physics B |
Citação: | Carmelo, J. M. P., Čadež, T., & Sacramento, P. D. (2020). Bethe strings in the dynamical structure factor of the spin-1/2 Heisenberg XXX chain. Nuclear Physics B, 960, 115175. doi: https://doi.org/10.1016/j.nuclphysb.2020.115175 |
Resumo(s): | Recently there has been a renewed interest in the spectra and role in dynamical properties of excited states of the spin-1/2 Heisenberg antiferromagnetic chain in longitudinal magnetic fields associated with Bethe strings. The latter are bound states of elementary magnetic excitations described by Bethe-ansatz complex non-real rapidities. Previous studies on this problem referred to finite-size systems. Here we consider the thermodynamic limit and study it for the isotropic spin-1/2 Heisenberg XXX chain in a longitudinal magnetic field. We confirm that also in that limit the most significant spectral weight contribution from Bethe strings leads to (k,ω)-plane gapped continua in the spectra of the spin dynamical structure factors S (k,ω) and S (k,ω)=S (k,ω). The contribution of Bethe strings to S (k,ω) is found to be small at low spin densities m and to become negligible upon increasing that density above m≈0.317. For S (k,ω), that contribution is found to be negligible at finite magnetic field. We derive analytical expressions for the line shapes of S (k,ω), S (k,ω)=S (k,ω), and S (k,ω) valid in the (k,ω)-plane vicinity of singularities located at and just above the gapped lower thresholds of the Bethe-string states's spectra. As a side result and in order to provide an overall physical picture that includes the relative (k,ω)-plane location of all spectra with a significant amount of spectral weight, we revisit the general problem of the line-shape of the transverse and longitudinal spin dynamical structure factors at finite magnetic field and excitation energies in the (k,ω)-plane vicinity of other singularities. This includes those located at and just above the lower thresholds of the spectra that stem from excited states described by only real Bethe-ansatz rapidities. +− xx yy zz −+ +− xx yy zz |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/73356 |
DOI: | 10.1016/j.nuclphysb.2020.115175 |
ISSN: | 0550-3213 |
Versão da editora: | https://www.sciencedirect.com/science/article/pii/S0550321320302613 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDF - CEP - Artigos/Papers (with refereeing) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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20-DSFXXX.pdf | 762,64 kB | Adobe PDF | Ver/Abrir |
Este trabalho está licenciado sob uma Licença Creative Commons