arXiv:cond-mat/9701097 · Physical Review Letters
Pseudogaps and Their Interplay with Magnetic Excitations in the Doped 2D Hubbard Model
R. Preuss, Werner R. Hanke, C. Gröber, Hans Gerd Evertz
Abstract
On the basis of quantum Monte Carlo simulations of the two-dimensional Hubbard model which cover the doping range from the underdoped to the overdoped regime, we find that the single-particle spectral weight $A(\stackrel{\ensuremath{\rightarrow}}{k},\ensuremath{\omega})$ qualitatively reproduces both the momentum ( ${d}_{{x}^{2}{\ensuremath{-}y}^{2}}$ symmetry) and doping dependence of the pseudogap as found in photoemission experiments. The drastic doping dependence of the spin response ${\ensuremath{\chi}}_{s}(\stackrel{\ensuremath{\rightarrow}}{q},\ensuremath{\omega})$, which is sharp in both $\stackrel{\ensuremath{\rightarrow}}{q}[\ensuremath{\approx}(\ensuremath{\pi},\ensuremath{\pi})]$ and $\ensuremath{\omega}$ in the underdoped regime but broad and structureless otherwise, identifies remnants of the antiferromagnetic order as the driving mechanism behind the pseudogap and its evolution with doping.