| 摘要 |
A method and a device (1) for measuring strong magnetic fields on a nanoscale are proposed. The device (1) comprises a positioning element (3) for positioning a magnetic-field-dependent photoluminescent (MFDP) particle (9) such as a Nitrogen-Vacancy center, a laser serving as a light source (11) for illuminating the MFDP particle (9), a microwave generator (15) for irradiating the MFDP particle (9) with electromagnetic microwave radiation, a photodetector (17) for detecting photoluminescence from the MFDP particle (9) and a controller (19). The controller (19 is adapted to controlling the positioning element (3), the light source (11), the microwave generator (15) and an external magnetic field generator (21), such as a hard disk write/read head, in accordance with a the method comprising: (a) positioning the MFDP particle (9); (b) performing manipulations for bringing the MFDP particle (9) into a predetermined excitation level; (c) ramping up a magnetic flux density (B); (d) irradiating the MFDP particle (9) with electromagnetic microwave radiation in a specific frequency range; (e) ramping down the magnetic flux density; and (f) detecting a quantum state of the MFDP particle e.g. by measuring an intensity of photoluminescence of the MFDP particle. In this way, spin preparation and readout is always performed in the low-field regime, while spectroscopy can be performed in an arbitrary high magnetic field. Thereby, strong magnetic fields with B > 10mT may be measured at nanoscales, allowing e.g. for imaging of hard disc write heads' magnetic field with simultaneously sub-nm resolution, nanoTesla sensitivity and Tesla dynamic range. |
