Nitrogen-vacancy centers close to surfaces

Defects in solid-state systems are responsible for much of what we take for granted in modern society, with applications ranging from electronics and lasers, to metallic alloys with tailored properties, and the unique characteristics of gemstones. As we enter the age of quantum technology, solid-state defects are also having their say, with substantial research focused on using their properties for fundamental tests of quantum mechanics, storage of quantum information, and investigations of quantum decoherence. Two of the most exciting prospects of quantum technology are the creation of computers that take advantage of quantum rather than classical laws to outperform current devices, and the realization of highly sensitive magnetometers limited only by quantum uncertainty. In pursuit of these two goals, many proposals and proof-of-principle experiments have been performed in the solid-state, which required location of defects very close to the host crystal's surface. This article reviews recent work on creation of nitrogen-vacancy centers near the diamond surface and experiments toward the realization of these goals.