Color centers in diamonds serve as gyroscopes
Practical evidence for usability of diamond color centers as rotation sensors
6 December 2021
When we turn our head, our brain realizes this rotation primarily through visual impression, through what we see. Technical devices, however, rely on gyroscopes, i.e., rotation sensors. Among other things, these are important for navigation. In an airplane's autopilot, for example, a gyroscope detects the three different types of rotation that the plane can perform: it can roll by turning one wing down and the other up, pull the nose up or down (pitch), or turn relative to the ground (yaw). Furthermore, gyroscopes are also important in vehicles on the ground, such as autonomous cars. The research group led by Professor Dr. Dmitry Budker published their idea of using color centers in diamonds as gyroscopes already back in 2012. Now the researchers have been able to provide practical proof, which they published recently in Science Advances.
Color centers in diamonds already used to measure magnetic fields
"We and other groups have used these color centers to measure magnetic fields for several years already,” said Budker, a physicist at Johannes Gutenberg University Mainz (JGU) and at the Helmholtz Institute Mainz (HIM). HIM is jointly funded by Mainz University and the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt. "In principle, the measurement of rotations works as with a magnetometer, but some challenges arise.” For example, the sensor must ignore fluctuating magnetic fields in order to measure rotations. Budker and his team were able to address this problem. On the one hand, instead of electron spins they use nuclear spins, which have a much smaller magnetic moment and therefore lower sensitivity to magnetic fields, for gyroscopy. On the other hand, the scientists were able to shield external magnetic fields to a large extent and still maintain a very stable bias magnetic field internally to generate the measurement effect, which also hardly reacts to temperature fluctuations. Should fluctuating magnetic fields occur in the external space, the color centers do not "see" them. Dr. Peter Blümler of Mainz University addressed the questions and challenges surrounding this magnetic field. The experiments and the first proof were achieved by Dr. Andrey Jarmola and Budker's former PhD student Dr. Sean Lourette at the University of California at Berkeley.
Thus, the researchers report two innovations in their recent paper in Science Advances. First, they were able to realize their 2012 idea and use diamond color centers as gyroscopes. Second, they worked out a technical way to make it happen. However, there are still more challenges to overcome before the method is feasible in everyday applications.