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Bond-versus-site doping models for off-chain-doped Haldane-gap system Y$_2$ Ba Ni O$_5$

Jizhong Lou·Shaojin Qin·Zhaobin Su·Lu Yu
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Abstract

Using the density matrix renormalization-group technique, we calculate the impurity energy levels for two different effective models of off-chain doping for quasi-one-dimensional Heisenberg chain compound Y$_2$ Ba Ni O$_5$: ferromagnetic bond doping and antiferromagnetic site spin-1/2 doping. Thresholds of the impurity strength for the appearance of localized states are found for both models. However, the ground-state and low-energy excitations for weak impurity strength are different for these two models and the difference can be detected by experiments.

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Jizhong Lou, Shaojin Qin, Zhaobin Su, Lu Yu. 1998-11-06. Bond-versus-site doping models for off-chain-doped Haldane-gap system Y$_2$ Ba Ni O$_5$. https://doi.org/10.1103/physrevb.58.12672

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