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Magnon and Hole Excitations in the Two-Dimensional Half-filled Hubbard Model

Weihong Zheng·Rajiv R. P. Singh·J. Oitmaa·O. P. Sushkov·C. J. Hamer
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Abstract

Spin and hole excitation spectra and spectral weights are calculated for the half-filled Hubbard model, as a function of $t/U$. We find that the high energy spin spectra are sensitive to charge fluctuations. The energy difference $Δ(π,0)- Δ(π/2,π/2)$, which is negative for the Heisenberg model, changes sign at a fairly small $t/U\approx 0.053(5)$. The hole bandwidth is proportional to $J$, and considerably larger than in the t-J models. It has a minimum at ($π/2,π/2$) and a very weak dispersion along the antiferromagnetic zone boundary. A good fit to the measured spin spectra in La$_2$CuO$_4$ at $T=10K$ is obtained with the parameter values $U=3.1{\rm eV}$, $t=0.35{\rm eV}$.

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Weihong Zheng, Rajiv R. P. Singh, J. Oitmaa, O. P. Sushkov, C. J. Hamer. 2005-01-03. Magnon and Hole Excitations in the Two-Dimensional Half-filled Hubbard Model. https://doi.org/10.1103/physrevb.72.033107

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