Tunneling magnetoresistance modulation in a magnetic tunnel junction with a ferroelectric barrier.

A simple model is developed to investigate the potential profile changes due to mechanical stress at the ferromagnetic/ferroelectric interfaces of ferromagnetic-ferroelectric-ferromagnetic tunnel junctions with an ultrathin ferroelectric barrier. The potential changes associated with the polarization variation have significant effects on the tunneling conductance of the junctions. The discovered effect is illustrated by the example of a multiferroic tunnel junction in which approximately four orders of changes of the tunneling conductance and several-fold changes of the tunneling magnetoresistance (TMR) are observed due to the spin-flip induced nanomechanical stress. The TMR modulation effect is essential for realization of novel spintronics nano-devices as well as being useful for investigating fundamental aspects of the spin transfer.