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تسجيل مستخدم جديدCritical properties of the half-filled Hubbard model in three dimensions
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By means of the dynamical vertex approximation (D$Gamma$A) we include spatial correlations on all length scales beyond the dynamical mean field theory (DMFT) for the half-filled Hubbard model in three dimensions. The most relevant changes due to non-local fluctuations are: (i) a deviation from the mean-field critical behavior with the same critical exponents as for the three dimensional Heisenberg (anti)-ferromagnet and (ii) a sizable reduction of the Neel temperature ($T_N$) by $sim 30%$ for the onset of antiferromagnetic order. Finally, we give a quantitative estimate of the deviation of the spectra between D$Gamma$A and DMFT in different regions of the phase-diagram.
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