Probing the pseudogap and beyond in the hole- and electron-doped Hubbard model

We calculate high-resolution angle-resolved photoemission spectroscopy (ARPES) of the Hubbard model using the unbiased determinant quantum Monte Carlo algorithm, revealing an asymmetry between electron and hole doping. For high doping, electron doping exhibits more coherent quasiparticles and stronger antiferromagnetic correlations compared to hole doping, which manifest in ARPES, transport, and thermodynamic properties. At low doping, a nodal-antinodal dichotomy on the Fermi surface is observed, similar to cuprate experiments. For hole doping, the spectral weight at the antinodal point is suppressed at lower temperatures, indicating a transition towards the pseudogap. The simulated nuclear magnetic resonance pseudogap temperature, obtained by downturns in Knight shift and the spin relaxation rate divided by temperature, shows no definitive correlation with the temperature determined by spectroscopy. Analysis of the self-energies indicates the spectral pseudogap is due to the proximity to the Mott gap. Our findings suggest the observed pseudogap does not arise from explicit symmetry breaking, but should be understood as a transitional crossover state driven by strong correlation effects.