Gyroscopes are employed ubiquitously, from rotation sensors in portable devices and cars to aerospace technologies. Modern devices, built on atomic and solid-state systems, presume tradeoff between long-term stability and sensitivity. We are developing solid-state gyroscopes based on nitrogen vacancy center in diamond.
A distinct feature of our project is very high stability of the gyroscope – practically drift-free. Such stability is achieved, in the first place, by a fact that momentum of nitrogen nucleus is constant, not changing in time, in contrary to MEMS gyroscopes, which mechanical characteristics change in time significantly. However, this advantage does not imply immunity to environmental conditions, such as magnetic fields and temperature.
Measurement method of absolute rotation speed is based on detecting nuclear spins of an ensemble of NV-centers (figure 1, figure 2).
Рисунок 1. NV-center structure in diamond lattice
Рисунок 2. Energy state of NV-center ground state
The rotation measurement method consists of:
Conversion NV-centers ensemble and surrounding nuclear spins to spin sensitive state (initialization);
Control of the system during measurement state;
Rotation information readout by acquiring phase, accumulated during free precession time
Block diagram of the quantum gyroscope based on diamond NV-centers consists of: NV-centers diamond plate, RF pulses control system, optical pumping and acquiring system, constant magnetic field source; simplified block diagram on figure 3.
Figure 3. Quantum gyroscope block diagram
Technology advantages are:
The solid-state nuclear spin technology has number of advantages, such as small size and feasibility of being integrated into chip devices. Theoretically achievable gyroscope performance:
Small sensor size: less than 1 cm^3.
High spectrum sensitivity: 0.3х10^-3 degrees/hour.
Zero drift: ~10^-3 degress/hour.
Figure 4. Quantum gyroscope sensing element
Figure 5. Laboratory prototype
A laboratory prototype of NV-centers based gyroscope optical block has been built, dimensions are 10x10x20 cm. Rotation and scale coefficient measurements have been conducted.