Giant piezoelectric resistance in ferroelectric tunnel junctions.

The effect of an applied mechanical stress on the tunneling conductance of a ferroelectric tunnel barrier between substrates and dissimilar electrodes is studied. Using a thermodynamic model and taking into account polarization charge screening in the electrodes and the near-surface inhomogeneous polarization distribution, the tunneling conductance is calculated as a function of the applied stress. It is found that reversing an applied stress can also change the tunnel barrier sufficiently to produce an effect similar to the giant electro-resistance one due to polarization reversal, which is particularly significant near the stress-dependent paraelectric/ferroelectric phase transition. Indeed, the sensitivity is adequate for high-sensitivity electronic and mechanical sensors, memories and other nanodevices.