Control of superconductivity by means of electric-field-induced strain in superconductor/piezoelectric hybrids

The controlled modification of superconductivity by any means, specifically in hybrid systems, has attracted much interest in the recent decades. Here, we present experimental data and phenomenological modeling on the control of T C of superconducting (SC) Nb thin films, with thickness 3 nm ≤ dNb≤50 nm, under the application of in-plane strain, S(E ex ) induced by an external out-of-plane electric field, E ex to piezoelectric (PE) single crystals, namely, (1-x)Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 (PMN-xPT), with x = 0.27 and 0.31. We report experimental modification of T C of Nb by E ex , accurately described by a phenomenological model that incorporates the constitutive relation S(E ex ) of PMN-xPT. The systematic experimental-phenomenological modeling approach introduced here is generic and paves the way for an understanding of the underlying physical mechanisms in any SC/PE hybrid.