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arXiv · 1104.3633

Determination of Boundary Scattering, Intermagnon Scattering, and the Haldane Gap in Heisenberg Chains

Hiroshi Ueda·Koichi Kusakabe
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Abstract

Low-lying magnon dispersion in a S=1 Heisenberg antiferromagnetic (AF) chain is analyzed using the non-Abelian DMRG method. The scattering length $a_{\rm b}$ of the boundary coupling and the inter-magnon scattering length $a$ are determined. The scattering length $a_{\rm b}$ is found to exhibit a characteristic diverging behavior at the crossover point. In contrast, the Haldane gap $Δ$, the magnon velocity $v$, and $a$ remain constant at the crossover. Our method allowed estimation of the gap of the S=2 AF chain to be $Δ= 0.0891623(9)$ using a chain length longer than the correlation length $ξ$.

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Hiroshi Ueda, Koichi Kusakabe. 2011-07-26. Determination of Boundary Scattering, Intermagnon Scattering, and the Haldane Gap in Heisenberg Chains. https://doi.org/10.1103/physrevb.84.054446

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