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Quantum antiferromagnetism in the d=3 Hubbard model --- a spin-fluctuation approach

Avinash Singh
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Abstract

A self-consistent spin-fluctuation theory is developed to obtain T_N vs. U for the half-filled Hubbard antiferromagnet in the whole U/t range. Good agreement is obtained in the strong coupling limit with the high-temperature series-expansion result for the equivalent Heisenberg model. Quantum, spin-fluctuation correction to the sublattice magnetization is also obtained for all U at the one-loop level. A spin picture is used throughout, and quantum effects are incorporated through transverse spin fluctuations, which are evaluated in the RPA using a new method.

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Avinash Singh. 1998-05-28. Quantum antiferromagnetism in the d=3 Hubbard model --- a spin-fluctuation approach. https://arxiv.org/abs/cond-mat/9802047

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