Spin diffusion in the double-exchange model at T = ∞

The process of spin diffusion within the double-exchange model is studied on a Bethe lattice in infinite dimension at T=infinity. In the absence of electron hopping, the spin-current correlation function oscillates with a period inversely proportional to the Hund's coupling and the spin-diffusion coefficient D vanishes. Electron hopping causes the correlation function to decay with time and yields a value for D proportional to the electron bandwidth.