The Spin Stiffness and the Transverse Susceptibility of the Half-filled Hubbard Model

Abstract

The $T=0$ spin stiffness ${\rho }_s$ and the transverse susceptibility ${\chi }_{\perp }$ of the square lattice half-filled Hubbard model are calculated as a function of the Hubbard parameter ratio $U/t$ by series expansions around the Ising limit. We find that the calculated spin-stiffness, transverse susceptibility, and sublattice magnetization for the Hubbard model smoothly approach the Heisenberg values for large $U/t$. The results are compared for different $U/t$ with RPA and other numerical studies.

9 Revtex pages, 3 Postscript figures, Europhys. Lett. in press