Quantum information science with rare earths

Realization of practical quantum communication, sensing, and computing critically depends on suitable materials that offer specific combinations of physical properties. Identifying and designing physical systems for use as qubits, the basic units of quantum information, are critical steps in the development of quantum information science. Among the possibilities in the solid state, defect states in wide gap materials stand out for robustness – their quantum states can be manipulated with high fidelity at finite temperature. Solid-state materials such as rare earth ions into wide band gap crystals are one of the most promising candidates for the quantum information processing. We provide an overview of rare earth-doped material properties and summarize some of the most promising oxide host materials studied from ab-initio electronic structure methods that take care of critically important electron correlation, spin orbit coupling, crystal field, quadrupolar and hyperfine interactions, and Zeeman effect to identify and realize quantum states in the gap regime.