Elastic Amplification from Negative Capacitance

Ferroelectrics under suitable electric boundary conditions can present a negative capacitance response, whereby the total voltage drop across the ferroelectric opposes the externally applied bias. When the ferroelectric is in a heterostructure, this behavior yields a voltage amplification in the other elements, an effect that could be leveraged in low-power electronic devices. Interestingly, the mentioned voltage amplification should have an accompanying elastic effect. Specifically, in the typical case in which the materials in contact with the ferroelectric are nonpolar dielectrics, those should present an enhanced electrostrictive response. Here, we use atomistic simulations-of model PbTiO_{3}/SrTiO_{3} ferroelectric/dielectric superlattices displaying negative capacitance-to show that this is indeed the case: we reveal the enhanced elastic response of the dielectric layer and show that it is clearly linked to the voltage amplification. We argue that this "elastic amplification" could serve as a convenient experimental fingerprint for negative capacitance. Further, we propose that it may be of interest on its own, e.g., for the development of low-power electromechanical actuators.