What is the fine-grained topic of the following text: On the hard side, we study quantum magnets, superconductors, topological materials, magnetic nanostructures and quantum nanowires using a variety of experimental techniques, including neutron scattering, optical, and terahertz spectroscopy; synthesize and characterize new solid-state materials; and model theoretically novel states of matter such as topological insulators, Weyl semimetals, and quantum spin liquids. Only return the topic.
Study of Quantum Materials and Solid-State Materials using Experimental Techniques and Theoretical Models