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

TL;DR

This paper calculates the spin stiffness and transverse susceptibility of the half-filled Hubbard model at zero temperature using series expansions, showing their smooth approach to Heisenberg model values as interaction strength increases.

Contribution

It provides a detailed series expansion analysis of spin stiffness and susceptibility across interaction regimes, connecting Hubbard and Heisenberg models.

Findings

Spin stiffness and susceptibility approach Heisenberg values at large U/t.

Results agree with RPA and other numerical methods.

Smooth variation of magnetic properties with U/t.

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.