Nanotube spin defects for omnidirectional magnetic field sensing

Area of Science:

• Quantum sensing
• Materials science
• Nanotechnology

Background:

• Optically addressable spin defects in 3D crystals and 2D van der Waals (vdW) materials are key for nanoscale quantum sensing.
• Spin defects in 1D vdW nanotubes offer unique advantages due to their small size and lack of dangling bonds.
• Previously, optically detected magnetic resonance of spin defects in nanotubes had not been achieved.

Purpose of the Study:

• To report the observation of single spin color centers in boron nitride nanotubes (BNNTs).
• To investigate the properties of these spin defects for quantum sensing applications.
• To demonstrate a novel method for scanning probe magnetometry using BNNTs.

Main Methods:

• Observation of single spin color centers in BNNTs at room temperature.
• Characterization of the spin S=1/2 ground state and its lack of intrinsic quantization axis.
• Development of a method for deterministic transfer of BNNTs onto cantilevers for scanning probe magnetometry.

Main Results:

• Successfully observed single spin color centers in BNNTs at room temperature.
• Demonstrated that BNNT spin defects enable orientation-independent magnetic field sensing.
• Utilized BNNTs to observe anisotropic magnetization of a 2D magnet, overcoming limitations of conventional spin defects.
• Showcased scanning probe magnetometry using a BNNT on a cantilever.

Conclusions:

• The observed BNNT spin defects are suitable for orientation-independent nanoscale quantum sensing.
• This work opens avenues for atomic-scale quantum sensing of magnetic fields in any direction.
• The developed techniques pave the way for advanced magnetometry and quantum information processing.