Scientists at University of Stuttgart have discovered a completely new type of magnetism in materials that are only a few atoms thick.
Working with international partners, the research team showed that when certain ultra-thin layers are stacked and slightly twisted, they can produce magnetic behavior never seen before.
The findings, published in Nature Nanotechnology, could help pave the way for future generations of ultra-dense and energy-efficient data storage.
As the world produces more and more digital information, storing data reliably in smaller and smaller spaces is becoming a major challenge.
Magnetic storage devices—such as hard drives—rely on tiny magnetic regions to represent information.
To increase storage density, scientists need new magnetic states that are both extremely small and very stable. This is exactly where the Stuttgart team’s discovery becomes important.
The research was led by Jörg Wrachtrup, head of the Center for Applied Quantum Technologies at the university.
His team studied a two-dimensional material made from chromium iodide, consisting of just four atomic layers.
While this material has been studied before, the researchers found something entirely new when they slightly rotated two pairs of layers relative to each other.
This tiny twist turns out to have a big effect. It creates a previously unknown magnetic state that can be precisely controlled by adjusting how electrons interact across the layers. Even more impressive, this magnetism remains stable despite disturbances from the surrounding environment, a key requirement for any real-world technology.
The twisted structure gives rise to objects known as skyrmions. These are extremely small, swirling magnetic patterns that behave a bit like knots.
Skyrmions are especially exciting because they are naturally stable and can serve as robust carriers of information. Although skyrmions have been observed in other materials before, this is the first time they have been created and directly detected in a twisted, atom-thin magnetic system.
Seeing these effects was not easy. The magnetic signals involved are incredibly weak—far too weak for conventional microscopes. To solve this problem, the researchers used a highly sensitive quantum microscope based on nitrogen-vacancy centers in diamond. These tiny defects in diamond crystals act as quantum sensors, capable of detecting minuscule magnetic fields with exceptional precision. This technique has been developed and refined at Stuttgart over many years and was crucial to the success of the experiment.
Beyond potential applications, the discovery also challenges existing theories of magnetism. The results suggest that current models do not fully explain how electrons behave collectively in ultra-thin magnetic materials. Refining these theories could open the door to even more unexpected discoveries in two-dimensional physics.
Together, the findings show that atom-thin materials still hold many surprises—and that even a slight twist can unlock entirely new physical worlds.
