Color centers in diamonds serve as gyroscopes
Practical evidence for usability of diamond color centers as rotation sensors
This news is based on a press release by Johannes Gutenberg University Mainz.
When we turn our head, our brain realizes this rotation primarily through the visual impression — that is, through what we see. Technical devices, on the other hand, 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, i.e. turn one wing down and the other up, pull the nose up or down (pitch), or turn relative to the ground (yaw). Gyroscopes are also important in vehicles on the ground, such as autonomous cars.
The research group led by Prof. 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. They recently published their results in the journal Science Advances.
Color centers in diamond already used to measure magnetic fields
“We and other groups have already used these color centers to measure magnetic fields for several years,” explains Budker, a physicist at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM), which, in addition to the university, is also funded by 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, however. On the one hand, they use nuclear spins instead of electron spins for gyroscopy, which have a much smaller magnetic moment and therefore lower sensitivity to magnetic fields. 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 from JGU addressed the questions and challenges surrounding this magnetic field. However, 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 paper. 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. (JGU/CP)