Defect in solids are an emerging class of quantum systems with potential use in various areas of quantum technology like quantum communication, information processing and precision sensing. Defects are found in 2D materials as well as bulk. Their quantum properties on the one hand mimic atomic systems but as well reveal molecular or solid state properties. The talk shall highlight two particular use of defects for quantum technology. 1) As optically active defects couple to light fields. They are excellent systems for quantum repeater nodes. They both show strong interaction with the light field and on the other hand do have very good quantum memory capabilities due to local nuclear spins. I will show efficient storage of photon to nuclear spin coherence and discuss the potential for generating strings of entangled photons using single defect. 2) Diamond defects are excellent tools for nanoscale quantum sensing. The long spin coherence times of such defects even under ambient conditions close to surfaces make them highly suited for spin-based detection of various quantities. The talk shall describe nanoscale sensing of electric, magnetic fields, temperature etc. utilizing spin quantum sensors. Applications in such diverse areas like solid-state physics or cellular biology shall be discussed.
