Charge and Spin Thermopower in Double-Barrier Magnetic Tunnel Junctions with a Semiconductor Spacer

The charge and spin thermopower in doublebarrier magnetic tunnel junctions with a semiconductor (e.g. GaAs) spacer (DBMTJs-SC) are studied using nonequilibrium Green's function (NEGF) formalism in the linear response regime. The results show oscillatory behavior with an increase of the SC spacer thickness due to the resonant tunneling effect through the DBMTJs-SC. Effects of the average temperature of the junctions and the spinsplitting of the ferromagnetic (FM) contacts on the charge and spin thermopower are also described. It is found that the results show a magnitude enhancement at the specific thicknesses of the SC spacer (resonant positions) compared with the other thicknesses.