What happens when you squeeze materials really hard? They can change in surprising ways—sometimes losing their magnetism, sometimes even becoming superconductors. To study these changes, scientists use a tool called a diamond anvil cell—basically two diamonds pressing on a material until it experiences pressures similar to those deep inside planets.
The problem? It’s tough to see what’s going on in that tiny space under such crushing force. Traditional tools can’t squeeze inside.
Now, researchers have created a new kind of quantum sensor that finally solves this challenge.
A paper-thin sensor that glows under pressure
The team used a sheet of a crystal called hexagonal boron nitride (hBN)—just one-thousandth the thickness of a hair. Inside this sheet are tiny “defects” that behave like glowing quantum sensors. Think of them like super-sensitive light bulbs: their glow shifts depending on how much stress or magnetism they feel.
When placed inside the diamond anvil cell, this sheet sits right next to the material being studied. That closeness means it can detect changes with far more precision than older methods.
What did the sensor reveal?
- Stress maps under pressure
The sensor showed that at low pressure, stress is spread evenly. But once the pressure passed about one gigapascal (that’s around ten thousand times the air pressure at sea level), uneven stress patterns started to appear. It’s like seeing cracks in the road surface after heavy traffic—the pressure isn’t evenly distributed anymore. - A magnet that switches off
They placed a tiny flake of a magnetic material called Cr1+δTe2 on the sensor. At room temperature, it behaved like a normal magnet. But when the pressure reached about half a gigapascal, the magnetism suddenly vanished. When the pressure was released, the magnetism returned—though in a different form. It’s like flipping a light switch off and on, but the bulb glows in a different color when it comes back.
Why does this matter?
This new tool lets scientists:
- Watch materials change in real time under extreme pressure.
- Link stress and magnetism together, revealing how mechanical forces affect magnetic or electronic behavior.
- Explore exotic states of matter, such as superconductivity, which could one day power lossless electricity grids or superfast computers.
Because the sensor is flat and easy to stack, it can also work with other two-dimensional materials, paving the way for new electronic and quantum devices.
The big picture
For decades, scientists have known that pressure can unlock hidden properties in materials. The problem was seeing those changes clearly. With this new 2D quantum sensor, the diamond anvil cell turns into a kind of microscope for extreme conditions.
It’s a leap that could open doors in physics, geology, and materials science—helping us understand how matter behaves deep inside Earth, or how to design future technologies that thrive under stress.
Check out the cool YouTube video about this article!
Article derived from: He, G., Gong, R., Wang, Z. et al. Probing stress and magnetism at high pressures with two-dimensional quantum sensors. Nat Commun 16, 8162 (2025). https://doi.org/10.1038/s41467-025-63535-7
