Spin coherent quantum dynamics occurs in the electronic, magnetic
and optical behavior of many materials at room temperature,
including semiconductors (organic and inorganic), ferrites, and
complex oxides. Many effects are most dramatic at interfaces or in
hybrid structures, and some persist to the single-spin limit.
Predicting spin coherent properties requires integrating theoretical
techniques to address multiple material classes, and to cope with
energy scales ranging from far smaller than the thermal energy to
far larger. Quantum-coherent behavior then emerges from an interesting set of excited states and
the couplings among them, whose description challenges ab initio
approaches. These phenomena imply new categories of quantum
materials and technologies.