Resonant electron transmission through a finite quantum spin chain

Electron transport in a finite one-dimensional quantum spin chain (with ferromagnetic exchange) is studied within an s−d exchange Hamiltonian. Spin transfer coefficients strongly depend on the sign of the s−d exchange constant. For a ferromagnetic coupling, they exhibit a novel resonant pattern, reflecting the salient features of the combined electron-spin system. Spin-flip processes are inelastic and feasible at finite voltage or at finite temperature.