5 Nm-Scale Surface Evenness Movement Measurement Method Based On The Electron Spin In Diamond

The motion of a magnetic levitation structure can lead to low accuracy for magnetically suspended control moment gyros (MSCMG), artificial heart pumps or high precision stable platforms. Measuring this motion is important in orbital navigation and precision measurement technologies, but current methods are unable to measure it with high accuracy under a strong magnetic field around the magnetic levitation structure. Here, we present a method in which nitrogen-vacancy (NV) centers in diamond have been used as a sensor to detect the movement of the magnetic levitation structure. The NV quantum sensors probe the electric field around the suspension magnet induced by the magnet fluctuations. Based on the high sensitivity of 0.3 nT (root Hz)(-1), the resolution of motion was about 5 nm. Also, the dynamic movement of the magnetic levitation system has been recorded in real-time with a potential resolution of similar to pm as the magnetic field sensitivity of NV center was improved to similar to pT. Our method offers a novel route to measure and feedback control the magnetic levitation system for MSCMGs in satellite attitude or for magnetic pumps in artificial heart applications.