@article{oai:sucra.repo.nii.ac.jp:00013317,
 author = {飛田, 和男},
 issue = {5},
 journal = {PHYSICAL REVIEW B},
 month = {},
 note = {http://link.aps.org/abstract/PRB/v45/p2207 | http://link.aps.org/abstract/PRB/v45/p2207, The ground-state properties of the spin-1/2 Heisenberg chain, which has two exchange couplings (J > J') alternatingly, are studied. This model interpolates the spin-1 antiferromagnetic Heisenberg chain (AFHC) (J' --> - infinity, J > 0), the dimerized spin-1/2 AFHC (J' congruent-to J > 0), and the uniform spin-1/2 AFHC (J' = J > 0) continuously. The string order introduced by den Nijs-Rommelse and Tasaki changes continuously through the Haldane phase and the dimer phase to vanish at J = J'. It is at a maximum for J' = 0. This implies that the string order is related to the local singlet correlation in terms of the spin-1/2 model. The lowest excitation can be regarded as the renormalized triplet wave. The reversal of the anisotropy effect on the excitation spectrum of the spin-1 AFHC is also explained in a intuitive way based on this picture., text, application/pdf},
 pages = {2207--2212},
 title = {CROSSOVER BETWEEN THE HALDANE-GAP PHASE AND THE DIMER PHASE IN THE SPIN-1/2 ALTERNATING HEISENBERG CHAIN},
 volume = {45},
 year = {1992},
 yomi = {ヒダ, カズオ}
}