1993/10/26 by Makoto Kaburagi, Takashi Tonegawa · 4 citations
Materials Science · Physics and Astronomy · #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat
paper · pdf · doi:10.1143/jpsj.63.420
11 pages, plain TeX (Postscript figures are included), KU-CCS-93-002
arxiv created 1993/10/26 · openalex publication_date 1994/02/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Low-lying excited states as well as the ground state of the spin-1 antiferro- magnetic Heisenberg chain with a spin-1/2 impurity are investigated by means of a variational method and a method of numerical diagonalization. It is shown that 1) the impurity spin brings about massive modes in the Haldane gap, 2) when the the impurity-host coupling is sufficiently weak, the phenomenological Hamiltonian used by Hagiwara \it et al. in the analysis of ESR experimental results for NENP containing a small amount of spin-1/2 Cu impurities is equivalent to a more realistic Hamiltonian, as far as the energies of the low-lying states are concerned, 3) the results obtained by the variational method are in semi-quantitatively good agreement with those obtained by the numerical diagonalization.