The superconducting intermediate state is formed in elemental (type-I) superconductors as a complex pattern of normal and superconducting regions. Newly developed experimental techniques may lead to a substantial revision of our current understanding of this state. These techniques allow one to observe local magnetic fields of the intermediate state in real time and to measure them with extreemly high sensitivity. This research has connections to important questions of pattern formation in complex mathematical, geophysical, chemical and biological systems and even to the formation of galaxies. The project carries significant educational impact. Students of all levels will work on the project, each performing specific set of measurements. Some experiments will be part of the advanced solid-state physics laboratory. The project involves active domestic and international collaborations with the leading experts in the field, including those who initiated related studies decades ago. A workshop on pattern formation in type-I superconductors is planned at the end of the research term.
This individual investigator award will support comprehensive studies of the intermediate state in type-I superconductors. Unique experimental techniques, such as magneto-optical visualization of magnetic fields and pico-emu sensitive tunnel-diode susceptometry, combined with conventional methods, will be employed to understand the intermediate state in a broader context of pattern formation in highly nonlinear systems. The study of topological hysteresis and complex shape effects may lead to the identification of unusual thermodynamically equilibrium states and, ultimately, to substantial revisions of our current understanding of type-I superconductivity. The ability to continuously tune the system across a broad range of topologies using both temperature and magnetic field makes type-I superconductivity an ideal arena in which to study general questions of pattern formation in nonlinear systems. Connections to biological, chemical and astrophysical systems will be studied as part of this project. The project carries significant educational impact. Students of all levels will work on the project, each performing specific set of measurements. Some experiments will be part of the advanced solid-state physics lab. The project involves active domestic and international collaborations with the leading experts in the field, including those who initiated related studies decades ago. A workshop on pattern formation in type-I superconductors is planned at the end of the research term.
