A Fiber-coupled Scanning Magnetometer with Nitrogen-Vacancy Spins in a Diamond Nanobeam

• Main Authors: Li, Yufan, Gerritsma, Fabian A, Kurdi, Samer, Codreanu, Nina, Gröblacher, Simon, Hanson, Ronald, Norte, Richard, van der Sar, Toeno
• Format: Journal Article
• Language: English
• Published: 24-02-2023
• Subjects: Physics - Mesoscale and Nanoscale Physics
• DOI: 10.48550/arxiv.2302.12536

Magnetic imaging with nitrogen-vacancy (NV) spins in diamond is becoming an
established tool for studying nanoscale physics in condensed matter systems.
However, the optical access required for NV spin readout remains an important
hurdle for operation in challenging environments such as millikelvin cryostats
or biological systems. Here, we demonstrate a scanning-NV sensor consisting of
a diamond nanobeam that is optically coupled to a tapered optical fiber. This
nanobeam sensor combines a natural scanning-probe geometry with high-efficiency
through-fiber optical excitation and readout of the NV spins. We demonstrate
through-fiber optically interrogated electron spin resonance and
proof-of-principle magnetometry operation by imaging spin waves in an
yttrium-iron-garnet thin film. Our scanning-nanobeam sensor can be combined
with nanophotonic structuring to control the light-matter interaction strength,
and has potential for applications that benefit from all-fiber sensor access
such as millikelvin systems.