Superelastic Microstructures of Superconducting SrTi_0.996Nb_0.004O₃

Strain tuning is a useful method for probing exotic correlated states of matter. In practice, strain engineering has not kept up with the high demand for large, tunable strains in a versatile range of materials. In this work, we report scanning SQUID measurements performed on superconducting niobium-doped strontium titanate superelastic pillar-shaped microstructures. We observed that the superfluid density responded nontrivially to increasing uniaxial stress and we interpret this as the result of an evolution in the domain structure within the micropillar, as well as strain-induced changes of the superconducting pairing. The method which we have developed is a novel combination of quantum materials research and superelasticity. The tunability and large magnitude of strain that is possible with these micropillars as well as their potential for usage in a wide variety of bulk materials makes them an exciting tool for future studies of strain-sensitive quantum materials.