Superconductivity – the quantum state in which a metal loses all electrical resistance and exhibits magnetic flux expulsion (the Meissner-Ochsenfeld effect) – is one of the major research topics in condensed matter physics. However, in many important materials, superconductivity is not understood. Complex oxides are particularly interesting in this regard because of the wide temperature and composition ranges where superconductivity occurs, and because the origin of superconductivity is thought to differ for different oxide families. Here a team of scientists at University of Minnesota’s Center for Quantum Materials uncovered a remarkable universal feature shared by these distinct materials. The discovery was enabled by the development of a novel nonlinear magnetic response technique, an extremely sensitive probe of magnetism. The team found in experiments on three prominent classes of unconventional oxide superconductors – strontium titanate (STO), strontium ruthenate (SRO), and the cuprates (LSCO and Hg1201) – that upon cooling toward the macroscopic transition temperature Tc superconductivity emerges in a highly similar fashion (see Figure), despite dramatically different electronic properties and Tc values. Furthermore, the universal response follows highly unconventional, yet remarkably simple exponential behavior. It was also shown that this behavior above Tc can be influenced by intentionally inducing structural inhomogeneity into the materials via plastic deformation. This suggests that the origin of the universal behavior is related to intrinsic structural inhomogeneity, which is therefore an essential ingredient in the unconventional physics of all the studied systems.