We compute unbiased spectral functions of the two-dimensional Hubbard model by extrapolating Green functions, obtained from determinantal quantum Monte Carlo simulations, to the thermodynamic and continuous time limits. Our results clearly resolve the pseudogap at weak to intermediate coupling, originating from a momentum selective opening of the charge gap. A characteristic pseudogap temperature ${T}^{*}$ , determined consistently from the spectra and from the momentum dependence of the imaginary-time Green functions, is found to match the dynamical mean-field critical temperature, below which antiferromagnetic fluctuations become dominant. Our results identify a regime where pseudogap physics is within reach of experiments with cold fermions on optical lattices.We compute unbiased spectral functions of the two-dimensional Hubbard model by extrapolating Green functions, obtained from determinantal quantum Monte Carlo simulations, to the thermodynamic and continuous time limits. Our results clearly resolve the pseudogap at weak to intermediate coupling, originating from a momentum selective opening of the charge gap. A characteristic pseudogap temperature ${T}^{*}$, determined consistently from the spectra and from the momentum dependence of the imaginary-time Green functions, is found to match the dynamical mean-field critical temperature, below which antiferromagnetic fluctuations become dominant. Our results identify a regime where pseudogap physics is within reach of experiments with cold fermions on optical lattices.

arXiv:1205.6788Physical Review BOct 4, 201254 citations

The Two Dimensional Hubbard Model at Half-Filling. I. Convergent Contributions

Vincent Rivasseau

Journal of Statistical PhysicsFeb 1, 200217 citations

Variational Study of the Two-dimensional Hubbard Model at half-filling

Yung‐Chung Chen, Hui-Chun Chien, Chih-Tin Shih

Bulletin of the American Physical SocietyMar 14, 20060 citations

Pseudogap formation in the half-filled Hubbard model

Marco Vekić, Steven R. White

Using quantum Monte Carlo, we study the evolution of pseudogaps in the spectral weight function for a half-filled two-dimensional Hubbard model as a function of temperature and coupling constant. The formation of pseudogaps at finite temperature can be used to distinguish between three regimes: (1) a strong-coupling Mott-Hubbard regime, characterized by a pseudogap which persists even at high temperatures; (2) a weak-coupling spin-density-wave regime, characterized by the absence of a pseudogap at any finite temperature; and (3) an intermediate-coupling regime with mixed behavior, characterized by a pseudogap that appears at a finite temperature.Using quantum Monte Carlo, we study the evolution of pseudogaps in the spectral weight function for a half-filled two-dimensional Hubbard model as a function of temperature and coupling constant. The formation of pseudogaps at finite temperature can be used to distinguish between three regimes: (1) a strong-coupling Mott-Hubbard regime, characterized by a pseudogap which persists even at high temperatures; (2) a weak-coupling spin-density-wave regime, characterized by the absence of a pseudogap at any finite temperature; and (3) an intermediate-coupling regime with mixed behavior, characterized by a pseudogap that appears at a finite temperature.

Physical review. B, Condensed matterJan 1, 199368 citations

Formation of gaps in the two-dimensional half-filled Hubbard model

Steven R. White

Using a combination of quantum Monte Carlo and the maximum-entropy method, we have studied the formation of gaps and pseudogaps in the single-particle spectral weight function A(p,\ensuremath{\omega}) for the two-dimensional half-filled Hubbard Model. We present results for U/t=4 from lattices ranging from 4\ifmmode\times\else\texttimes\fi{}4 to 16\ifmmode\times\else\texttimes\fi{}16, and for inverse temperatures ranging from \ensuremath{\beta}=2 to \ensuremath{\beta}=12. We find that a pseudogap appears only when the spin-spin correlations are comparable to the size of the lattice. Since the spin-spin correlation length is known to diverge only at T=0, the implication is that in an infinite lattice there is no pseudogap except at T=0 for U/t=4.Using a combination of quantum Monte Carlo and the maximum-entropy method, we have studied the formation of gaps and pseudogaps in the single-particle spectral weight function A(p,\ensuremath{\omega}) for the two-dimensional half-filled Hubbard Model. We present results for U/t=4 from lattices ranging from 4\ifmmode\times\else\texttimes\fi{}4 to 16\ifmmode\times\else\texttimes\fi{}16, and for inverse temperatures ranging from \ensuremath{\beta}=2 to \ensuremath{\beta}=12. We find that a pseudogap appears only when the spin-spin correlations are comparable to the size of the lattice. Since the spin-spin correlation length is known to diverge only at T=0, the implication is that in an infinite lattice there is no pseudogap except at T=0 for U/t=4.

Physical review. B, Condensed matterSep 1, 199231 citations

A Configuration Interaction Approach to the Two Dimensional Hubbard Model Near Half-Filling

Greg Levine, Bat-el Friedman

APSMar 1, 19970 citations

{T}^{*}

, determined consistently from the spectra and from the momentum dependence of the imaginary-time Green functions, is found to match the dynamical mean-field critical temperature, below which antiferromagnetic fluctuations become dominant. Our results identify a regime where pseudogap physics is within reach of experiments with cold fermions on optical lattices.