MIT researchers have discovered a brand-new form of magnetism—called p-wave magnetism—that could open the door to ultra-fast, energy-efficient computer memory and processing technologies.
This discovery, published in Nature on May 28, marks the first time this unusual magnetic state has been observed, and it could be a major step toward next-generation “spintronic” devices that store and manipulate data using the spin of electrons instead of their charge.
Magnetism usually falls into two well-known categories.
In everyday magnets like those on your fridge, called ferromagnets, the electrons’ spins all point in the same direction, creating a strong magnetic field.
In antiferromagnets, the spins alternate directions and cancel each other out, so there’s no large-scale magnetism even though the material is still magnetic on a small scale.
The new type of magnetism blends features of both. The MIT team observed it in nickel iodide, a two-dimensional crystalline material they carefully made in the lab. In this material, the electron spins arrange themselves in a unique spiral pattern.
These spirals come in two mirror-image forms, much like your left and right hands. Although the overall magnetism cancels out, the spiral shape creates new, special behaviors.
What makes this discovery so exciting is that these spiral spin patterns can be flipped by applying a small electric field. This ability to switch the “handedness” of the spin spiral—turning a left-handed pattern into a right-handed one and vice versa—means that the direction of electron spins can be controlled electrically.
This is exactly what scientists working in the field of spintronics have been hoping for. Unlike traditional electronics, which move electrical charge, spintronics uses the spin of electrons to store and process information. This can potentially make devices much faster, smaller, and more energy-efficient.
To confirm their discovery, the researchers created ultra-thin flakes of nickel iodide and exposed them to circularly polarized light, which spins in a specific direction. They found that the spin of the electrons matched the direction of the light, proving the unique spiral configuration was affecting electron behavior as predicted by theory.
The researchers also applied electric fields to the material and found they could easily switch the direction of electron spins, generating a flow of electrons all spinning the same way—what’s known as a spin current.
This kind of control could be used to build memory bits or other components in spin-based computer chips, and it would use far less energy than today’s electronics.
The catch is that this behavior only appears at very low temperatures—around 60 kelvins, or below -350°F. That’s colder than liquid nitrogen, making it impractical for real-world use right now. But the researchers are hopeful that materials with similar properties can be found that work at room temperature.
This breakthrough was made possible with support from the National Science Foundation, the Department of Energy, and the U.S. Air Force. Scientists believe it represents a significant leap forward in the quest to build smaller, faster, and greener computing technology.
