Currents and Phases in Quantum Rings

Explore the fascinating world of quantum rings and their magnetic properties in this 31-minute conference talk presented by Kathryn Moler from Stanford University at the Fred Kavli Special Symposium on Quantum Matter & Quantum Information. Delve into the use of ring currents to access fundamental and topological properties of quantum states in charge-carrying particles. Discover how applying magnetic flux through a ring creates phase gradients and induces currents, which are measured using a scanning SQUID microscope. Journey through various quantum materials, from gold rings exhibiting persistent currents to superconducting aluminum rings. Learn about the remarkable agreement between theory and experiment in conventional metals and superconductors, setting the stage for studying superconducting rings interrupted by Josephson junctions. Gain insights into the current-phase relation of these junctions and the potential for observing 4pi-periodic currents in topological materials, which could serve as a smoking-gun signature for Majorana modes.