Compact dynamic cantilever magnetometry

A research team from the High Magnetic Field Laboratory, the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, has developed a compact dynamic cantilever magnetometer with a diameter of just 22 mm, achieving a magnetic moment sensitivity on the order of 10⁻¹⁷ A·m². 

"This breakthrough fills a technological gap in ultra-sensitive magnetic measurements for small, low-dimensional materials under high magnetic fields," said Prof. WANG Ning, a member of the team. 

The study was published in Review of Scientific Instruments.

Traditional vibrating sample magnetometers, though widely used, struggle with background noise and limited sensitivity—particularly under rapidly changing fields—making them unsuitable for detecting the weak magnetic signals of emerging quantum materials such as 2D magnets, superconductors, and topological materials.

To address this challenge, the team designed a new dynamic cantilever magnetometer using laser interferometry to detect magnetic properties through resonance frequency shifts. Unlike conventional systems, which require bulky positioning mechanisms and have probe diameters exceeding 100 mm, this new design features laser auto-focusing compensation. 

This innovation eliminates the need for heavy mechanical components and drastically reduces the probe diameter to 22 mm, allowing compatibility with various systems, including PPMS (26 mm aperture), Janis 9 T magnets (32 mm), and High-Field Magnet Facilities (32 mm).

Using this device, researchers successfully measured the magnetic properties of the 2D magnetic material Cr₂Ge₂Te₆ and detected quantum oscillations in ZrV₆Sn₆, demonstrating the system's outstanding performance in high-field, weak-signal detection.

This compact dynamic cantilever magnetometry is expected to provide strong technical support for frontier research areas such as low-dimensional magnetism, quantum states of matter, and biomagnetism, according to the team.