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arXiv:cond-mat/9501098

Bounds on the mass gap of the ferromagnetic XXZ chain

Bruno Nachtergaele

Published Jan 20, 1995• 1 citation
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Abstract

We prove rigorous lower and upper bounds for the mass gap of the ferromagnetic spin 1/2 XXZ chain. The two bounds coincide asymptotically in the Ising limit $Δ\to\infty$. Near the isotropic point, $Δ=1$, the estimates are good enough to determine the critical behaviour of the mass gap unambiguously. The derivation does not rely on exact solutions.

DOI
10.48550/arxiv.cond-mat/9501098

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We prove rigorous lower and upper bounds for the mass gap of the ferromagnetic spin 1/2 XXZ chain. The two bounds coincide asymptotically in the Ising limit Δ→∞Δ\to\inftyΔ→∞. Near the isotropic point, Δ=1Δ=1Δ=1, the estimates are good enough to determine the critical behaviour of the mass gap unambiguously. The derivation does not rely on exact solutions.
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