  We propose a sensitive and stable three-axis gyroscope in diamond. We achieve
high sensitivity by exploiting the long coherence time of the N14 nuclear spin
associated with the Nitrogen-Vacancy center in diamond, and the efficient
polarization and measurement of its electronic spin. While the gyroscope is
based on a simple Ramsey interferometry scheme, we use coherent control of the
quantum sensor to improve its coherence time as well as its robustness against
long-time drifts, thus achieving a very robust device with a resolution of
0.5mdeg/s/(Hz mm^3)^(1/2). 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.
