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Local impurities in 2D quantum antiferromagnets

V. N. Kotov·J. Oitmaa·O. Sushkov
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Abstract

The two-dimensional quantum Heisenberg antiferromagnet at zero temperature with two kinds of locally frustrating defects - isolated ferromagnetic bonds and impurity spins, is studied. For a quantum spin, coupled antiferromagnetically to the two sublattices, we find a local ground state transition. In the case of a ferromagnetic bond, the local magnetization is found to remain finite even for strong coupling, contrary to previous results, derived within the linear spin-wave approximation. Our results are based on an analytic approach, suitable to treat strong defect-environment interaction, as well as exact diagonalization studies. Technical details and some extension of this work can be found in cond-mat/9712281.

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V. N. Kotov, J. Oitmaa, O. Sushkov. 1998-01-01. Local impurities in 2D quantum antiferromagnets. https://doi.org/10.1016/s0304-8853(97)00844-5

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