Control of Both Superconducting Critical Temperature and Critical Current by Means of Electric-Field-Induced Reconfigurable Strain

The controlled modification of superconductivity by any means is a long-standing issue in low-temperature physics. In this work, we present data on the control of the superconducting properties of conventional low critical-temperature (T_C) Nb thin films with thickness (d_Nb) = 15 and 20 nm under application of reconfigurable strain, S induced by an external electric field, and E_ex to a piezoelectric (PE) single crystal, namely (1 − x)Pb(Mg_1/3Nb_2/3)O₃ − x PbTiO₃ (PMN-PT) with x = 0.30–0.31. The experimental results (reduction of T_C and critical current (J_C) on the order of 6% and 90–100%, respectively) are nicely reproduced with a phenomenological model that incorporates the constitutive relation S(E_ex) that describes the electro-mechanical response of the PE crystal to well-established formulas that describe T_C and J_C of the SC thin films.