Quantum Materials Group

The overarching goal of the Eley Quantum Materials Group is understand the role of disorder on the electronic and magnetic properties of quantum materials and devices.  Specifically, we study vortex-defect interactions in superconductors, skyrmion-defect interactions in magnetic materials, and the effects of the  material microstructure on energy loss in superconducting circuits. Vortices are topological excitations that appear in many different systems, including superconductors, magnets, superfluids, liquid crystals, and Bose-Einstein condensates. In superconductors, vortices are typically unwanted as their motion greatly limits the current carrying capacity and induces microwave energy loss. On the contrary, in certain chiral magnets and magnetic multilayers, vortex-like excitations called skyrmions are beneficial for use as information carriers in next-generation low-energy spintronic devices. We seek to develop a microscopic understanding of the complex interplay between vortices, material disorder, and thermal energy to mitigate the deleterious effects of superconducting vortices and exploit skyrmions in spintronics. Superconducting quantum circuits are limited by energy losses due to parasitic two-level fluctuators (TLFs), quasiparticle poisoning, and dissipative vortex motion. Despite numerous studies that have successfully tuned the effects of these decoherence mechanisms, the microscopic origin of TLFs and source of quasiparticles is usually unknown and no methods exist to eliminate these loss mechanisms.  To achieve these goals, our lab is capable of magnetometry, electrical transport measurements, and magnetic force microscopy (coming soon) in variable temperatures (down to the millikelvin range) and magnetic fields (up to several tesla)