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Spectral weight contributions of many-particle bound states and continuum

W. Zheng·C. J. Hamer·R. R. P. Singh
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Abstract

Cluster expansion methods are developed for calculating the spectral weight contributions of multiparticle excitations - continuum and bound states - to high orders. A complete 11th order calculation is carried out for the alternating Heisenberg chain. For $λ=0.27$, relevant to the material $Cu(NO_3)_2.2.5D_2O$, we present detailed spectral weights for the two-triplet continuum and all bound states. We also examine variation of the relative weights of one and two-particle states with bond alternation from the dimerized to the uniform chain limit.

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W. Zheng, C. J. Hamer, R. R. P. Singh. 2002-11-16. Spectral weight contributions of many-particle bound states and continuum. https://doi.org/10.1103/physrevlett.91.037206

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