Tunneling through two single molecular magnets in series arrangement junction in parallel/antiparallel situations

We investigate the spin-dependent tunneling transport in a heterostructure with two single molecular magnets (SMMs). The tunneling magnetoresistance (TMR) and negative differential conductance due to the strong resonant tunneling in the junction are demonstrated by the master equation approach. At low bias voltage, the device presents low/high resistant states with the initial states of the single molecular magnets parallel/antiparallel. Strong Coulomb repulsive interaction suppresses the current greatly in antiparallel situation. At high voltage, the middle system containing two SMMs tends to be non-polarized, and acts like ordinary quantum dots.

► Low/high resistant states with initial states parallel/antiparallel.
► Coulomb repulse suppresses the current in antiparallel situation.
► At high voltage, two SMMs tend to be non-polarized.
► Negative differential resistance in parallel situation.