A diamond-based scanning probe spin sensor operating at low temperature in ultra-high vacuum

Area of Science:

• Quantum Sensing
• Nanoscience
• Materials Science

Background:

• Nitrogen-vacancy (NV) centers in diamond are atomic-scale sensors for magnetic fields.
• Previous studies demonstrated NV center microscopy under ambient conditions.
• Operating NV sensors in cryogenic ultra-high vacuum (UHV) environments is challenging but offers benefits.

Purpose of the Study:

• To design and characterize an UHV low-temperature scanning probe microscope utilizing NV centers.
• To enable nanoscale magnetic field imaging and single spin detection in a controlled cryogenic UHV environment.
• To enhance target spin lifetimes and facilitate controlled sample preparation for molecular systems.

Main Methods:

• Integration of a tuning-fork atomic force microscope (AFM) with a high numerical aperture confocal microscope.
• Incorporation of radio-frequency (RF) field application capabilities for spin manipulation.
• Operation within an ultra-high vacuum (UHV) system achieving sample temperatures below 50 K.

Main Results:

• Successful operation of an NV center-based scanning probe microscope in a cryogenic UHV environment.
• Demonstration of magnetic resonance imaging using a magnetic AFM tip.
• Verification of stable sample temperatures (<50 K) under significant laser and RF excitation.

Conclusions:

• The developed instrument provides a platform for ultrasensitive nanoscale magnetic sensing at low temperatures.
• This UHV cryogenic setup expands the applicability of NV center microscopy to sensitive molecular systems.
• The system facilitates advanced studies of spin properties and magnetic phenomena at the nanoscale.