A robust, fiber-coupled scanning probe magnetometer using electron spins at the tip of a diamond nanobeam

• Published in: New journal of physics Vol. 26; no. 10; pp. 103031 - 103040
• Main Authors: Li, Yufan, Welker, Gesa, Norte, Richard, van der Sar, Toeno
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01-10-2024
• Subjects: Biological properties; diamond nanobeams; diamond nanophotonics; Efficiency; Electron spin; fiber-coupled sensor; Ion implantation; Magnetic fields; Microscopy; Nanoscience; Nitrogen; nitrogen-vacancy magnetometry; Optical coupling; Optical wireless; Optics; Physics; quantum sensing; Robustness; Sensors
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/ad8779

Fiber-coupled sensors are well suited for sensing and microscopy in hard-to-reach environments such as biological or cryogenic systems. We demonstrate fiber-based magnetic imaging based on nitrogen-vacancy (NV) sensor spins at the tip of a fiber-coupled diamond nanobeam. We incorporated angled ion implantation into the nanobeam fabrication process to realize a small ensemble of NV spins at the nanobeam tip. By gluing the nanobeam to a tapered fiber, we created a robust and transportable probe with optimized optical coupling efficiency. We demonstrate the imaging capability of the fiber-coupled nanobeam by measuring the magnetic field generated by a current-carrying wire. With its robust coupling and efficient readout at the fiber-coupled interface, our probe could allow new studies of (quantum) materials and biological samples.