Physical Society Colloquium

Spatially modulated superconductivity in microstructures

Katja Nowack

Department of Physics
Cornell University

The ability to spatially control the electronic properties of solids has led to landmark discoveries in condensed matter physics as well as new electronic applications. Although crystals of strongly correlated metals exhibit a diverse set of electronic ground states, few approaches to spatially modulate their properties exist. In this talk, I will discuss how we achieve spatial modulation of the superconducting state in focus ion beam (FIB) defined microstructures fabricated from single crystals of the heavy-fermion superconductor CeIrIn₅. In a nutshell, differential thermal contraction of the substrate and the microstructures induces a non-trivial strain field in the device. This strain field results in a complex pattern of superconductivity due to the dependence of the superconducting transition temperature on the strength and direction of strain. We directly image the spatially modulated superconductivity using scanning superconducting quantum interference device microscopy. Devices with different geometry show that the obtained spatial modulation of superconductivity can be tailored in agreement with predictions based on finite element simulations. These results offer a new approach to manipulate strain-sensitive electronic order on micrometer length scales in strongly correlated matter.