Spin Stiffness in the Hubbard model
arXiv:cond-mat/9510144 · doi:10.1088/0305-4470/29/1/008
Abstract
The spin stiffness of the repulsive Hubbard model that occurs in the hydrodynamic theory of antiferromagnetic spin waves is shown to be the same as the thermodynamically defined stiffness involved in twisting the order parameter. New expressions for are derived, which enable easier interpretation, and connections with superconducting weight and gauge invariance are discussed.
21 Pages LaTeX2e, to be published in Journal of Physics A