Fig. 4: Schematic representation of spin-dependent tunneling in an magnetic tunnel junctions (MTJ).

a Parallel configuration, where the magnetizations of the two FM layers (FM1 and FM2) are aligned, leading to lower resistance and higher tunneling probability for majority spin carriers. b Antiparallel configuration, where the magnetizations are opposite, increasing resistance and reducing tunneling efficiency due to the density of states (DOS) mismatch. The energy band diagrams below depict the spin-dependent DOS and tunneling probabilities for each configuration.