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
μmwithout 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
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.
In recent years, sensors based on hot atomic vapor cells have emerged as a compact and highly sensitive means of measuring magnetic fields. Such sensors have been deployed in the field for the measurement of, e.g. biological systems, representing a promising practical application of quantum technologies. However, it remains challenging to obtain high-resolution magnetic field images from these sensors, and in most cases the spatial resolution of the system is limited by the sensor size. Here, we demonstrate the combination of single-pixel imaging (SPI) techniques with an atom vapor. Faraday magnetometer to achieve microscopic magnetic field imaging. We demonstrate magnetic field imaging with a spatial resolution of
≈ 62.5μm, limited only by the resolution of our DMD projection system and the absence of magnetic shielding in our experimental setup.
Widefield quantum diamond microscopy is a powerful technique for imaging magnetic fields with high sensitivity and spatial resolution. However, current methods to approach the ultimate spatial resolution (<500 nm) are impractical for routine use as they require time-consuming fabrication or transfer techniques to precisely interface the diamond sensor with the sample to be imaged. To address this challenge, we have designed a co-axial sensor holder that enables simple, repeatable sensor–sample interfacing while being compatible with high numerical aperture (NA) optics. With our new design we demonstrate low standoffs <500 nm with a millimeter sized sensor. We also explore the relationship between spatial resolution and NA spanning from 0.13 to 1.3. The spatial resolution shows good agreement with the optical diffraction limit at low NA but deviates at high NA, which is shown to be due to optical aberrations. Future improvements to our design are discussed, which should enable magnetic imaging with <500 nm resolution in an accessible, easy-to-use instrument.