Pseudogaps and their Interplay with Magnetic Excitations in the doped 2D Hubbard Model

Abstract

On the basis of Quantum Monte Carlo simulations of the two-dimensional Hubbard model which cover the doping range from the under- to the over-doped regime, we find that the single-particle spectral weight $A(\vec{k},\omega )$ qualitatively reproduces both the momentum ($d_{x^2-y^2}$--symmetry) and doping dependence of the pseudogap as found in photoemission experiments. The drastic doping dependence of the spin response ${\chi }_s(\vec{q},\omega )$ which is sharp in both $\vec{q}(\approx (\pi ,\pi ))$ and $\omega$ in the under-doped regime but broad and structureless otherwise, identifies remnants of the antiferromagnetic order as the driving mechanism behind the pseudogap and its evolution with doping.

4 pages, Rev-Tex, includes 3 figures