Parallel single-shot measurement and coherent control of solid-state spins below the diffraction limit

Addressing the many and the individual The ability to coherently manipulate the quantum state of atomic defects in solid-state systems is a promising route to developing a platform for quantum technologies. A successful platform requires the interaction of many qubits in close proximity, as well as the ability to address each qubit individually, and, to date, such requirements have run counter to each other. Chen et al. devised an optical frequency-domain method with which they were able to simultaneously address many individual rare-earth ion defects (six at this point) with separations all within the diffraction limit of the control light. Because the approach is scalable to tens or hundreds of defects, it provides the prospect of realizing truly large-scale quantum processors. Science , this issue p. 592