Measurement of Microdisplacement by Spin Manipulated Magnetometer of Nitrogen Vacancy Centers With Magnetic Flux Concentration Structure

The diamond nitrogen-vacancy (NV) centers have stable spin-coherent properties at room temperature. They are easily initialized and read out, highly manipulable, and hold great promise for quantum precision measurements. In this article, we construct a magnetic flux concentration (MFC) structure combined with a quantum spin manipulated magnetometer of NV centers. This structure is further combined with a uniform spatial magnetic field gradient to achieve high-resolution microdisplacement (MD). MD measurement with and without MFC is realized using Ramsey’s principle. The sensitivity of MD measurement with MFC is 150.84 mV/mm, and the experimental test range is 105–107 mm. The resolution of MD detection has been experimentally verified to be 1.95
$\mu \text{m}$
without MFC and 49 nm with MFC. The resolution of MD detection has been improved by a factor of 39.8. The displacement shot-noise-limited sensitivity of the magnetometer can reach 0.21 nm/Hz
$^{\text {1/2}}$
. The results demonstrate that utilizing quantum spin manipulation and the MFC effect enables achieving both high resolution and rapid detection of MD for NV centers in systematic diamonds. This offers a novel approach for high-resolution MD measurement.