1997/09/30 by Peter Kopietz · 1 citation
Physics and Astronomy · #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.57.7829
published as Phys. Rev. B 57, 7829 (1998) · Discussion of gauge invariance and difference between transverse and longitudinal response added. Accepted for publication in Phys. Rev. B
arxiv created 1997/12/03 · openalex publication_date 1998/04/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We discuss analogies between the charge and spin response functions of itinerant magnets. We show that the spin analog of the charge stiffness is not given by the usual spin stiffness \ensuremathρs, but by the dynamic spin stiffness Ds, which is obtained from the dynamic spin conductance Gs(\ensuremathω) in the limit of vanishing frequency \ensuremathω. The low-frequency behavior of Gs(\ensuremathω) is used to define ideal spin conductors, normal spin conductors, and spin insulators. Assuming diffusive spin dynamics, we show that the spin-diffusion coefficient is proportional to limop_\stackrel\ensuremath→\ensuremathω0ReGs(\ensuremathω). We exploit this fact to develop an extrapolation scheme for the spin-diffusion coefficient in the paramagnetic phase of the Hubbard model.