Drude Weight, Optical Conductivity of Two-Dimensional Hubbard Model at Half Filling

Peter S. Riseborough

Hiroki Nakano, Yoshinori Takahashi, Masatoshi Imada

J. O. Lawson, Richard Smith

Lei Xu, Zhang Jun

We study the Drude weight D and optical conductivity of the two-dimensional (2D) Hubbard model at half filling with staggered magnetic flux (SMF). When SMF being introduced, the hopping integrals are modulated by the magnetic flux. The optical sum rule, which is related to the mean kinetic energy of band electrons, is evaluated for this 2D Hubbard Hamiltonian. Our present result gives the dependence of the kinetic energy, D and the optical conductivity on SMF and U. At half filling D vanishes exponentially with system size. We also find in the frequency dependence of the optical conductivity, there is δ-function peak at ω ≈ 2|m|U and the incoherent excitations begin to present themselves extended to a higher energy region.

H. Benthien, Eric Jeckelmann

W. Brenig