arXiv:1205.1494 · Physical Review A
Stable three-axis nuclear-spin gyroscope in diamond
Ashok Ajoy, Paola Cappellaro
Abstract
Gyroscopes find wide applications in everyday life from navigation and inertial sensing to rotation sensors in hand-held devices and automobiles. Current devices, based on either atomic or solid-state systems, impose a choice between long-time stability and high sensitivity in a miniaturized system. Here, we introduce a quantum sensor that overcomes these limitations by providing a sensitive and stable three-axis gyroscope in the solid state. We achieve high sensitivity by exploiting the long coherence time of the ${}^{14}$N nuclear spin associated with the nitrogen-vacancy center in diamond, combined with the efficient polarization and measurement of its electronic spin. Although the gyroscope is based on a simple Ramsey interferometry scheme, we use coherent control of the quantum sensor to improve its coherence time and robustness against long-time drifts. Such a sensor can achieve a sensitivity of $\ensuremath{\eta}\ensuremath{\sim}0.5\phantom{\rule{0.28em}{0ex}}(\mathrm{mdeg}\phantom{\rule{0.16em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1})/\sqrt{\mathrm{Hz}\phantom{\rule{0.16em}{0ex}}{\mathrm{mm}}^{3}}$ while offering enhanced stability in a small footprint. In addition, we exploit the four axes of delocalization of the nitrogen-vacancy center to measure not only the rate of rotation, but also its direction, thus obtaining a compact three-axis gyroscope.