Superconductivity and Magnetism

This program undertakes experimental and theoretical investigations of novel superconducting and magnetic materials that are important for fundamental physics and applications. It explores novel physical phenomena associated with superconductivity and its interplay with magnetism and determines the origins of these phenomena so as to promote use-inspired innovations. We investigate materials from macroscopic to nanoscale crystals and heterostructures under controlled environments using a wide range of sophisticated thermodynamic and dynamic characterization tools. One grand challenge pursuit is devoted to the new iron pnictides, which embody a new opportunity in the search for an isotropic high temperature superconductor. Another grand challenge pursuit is to develop novel strategies for controlling vortex dynamics by creating active, adaptive and smart vortex pinscapes to tailor the electromagnetic behavior of type II superconductors. In addition, we are also seeding promising new research into the spectral character of THz radiation from high temperature superconducting crystal micro-mesas, which has the potential for a new compact and portable THz source. We maintain leading programs in experiment and theory, with each deriving strong benefit from close mutual cooperation. Our present research focuses on: (i) exploring the multi-band nature of superconductivity in iron pnictide superconductors, (ii) developing nano-pinscapes to control vortex pinning and vortex liquid flow, (iii) investigating complex phenomena at the interface of superconductivity and magnetism in innovative hybrid heterostructures, and (iv) elucidating the physics of coherent THz electromagnetic wave generation by intrinsic Josephson junctions in crystal micro-mesas.