For decades, physicists believed that superconductivity and magnetism were fundamentally incompatible. Superconductivity is fragile: even a weak magnetic field can disrupt the delicate pairing of electrons that allows electrical current to flow without resistance. Magnetism, by its very nature, should destroy superconductivity.
And yet, in the past year, two independent experiments upended this assumption.
In two different quantum materials, researchers observed something that should not have existed at all: superconductivity and magnetism appearing side by side. One experiment involved rhombohedral graphene, while another focused on the layered crystal molybdenum ditelluride (MoTe₂). The findings stunned the condensed-matter physics community and reopened a fundamental question—how is this even possible?
Now, a new theoretical study from physicists at the Massachusetts Institute of Technology offers a compelling explanation. Writing in the Proceedings of the National Academy of Sciences, the researchers propose that under the right conditions, electrons in certain magnetic materials can split into fractional quasiparticles known as anyons—and that these anyons, rather than electrons, may be responsible for superconductivity.
If confirmed, the work would introduce a completely new form of superconductivity, one that survives magnetism and is driven by exotic quantum particles instead of ordinary electrons.
“Many more experiments are needed before one can declare victory,” said Senthil Todadri, William and Emma Rogers Professor of Physics at MIT, in a media statement. “But this theory is very promising and shows that there can be new ways in which the phenomenon of superconductivity can arise.”
A Quantum Contradiction Comes Alive
Superconductivity and magnetism are collective quantum states born from the behavior of electrons. In magnets, electrons align their spins, producing a macroscopic magnetic field. In superconductors, electrons pair up into so-called Cooper pairs, allowing current to flow without energy loss.
For decades, textbooks taught that the two states repel each other. But earlier this year, that belief cracked.
At MIT, physicist Long Ju and colleagues reported superconductivity coexisting with magnetism in rhombohedral graphene—four to five stacked graphene layers arranged in a specific crystal structure.
“It was electrifying,” Todadri recalled in a media statement. “It set the place alive. And it introduced more questions as to how this could be possible.”
Soon after, another team reported a similar duality in MoTe₂. Crucially, MoTe₂ also exhibits an exotic quantum phenomenon known as the fractional quantum anomalous Hall (FQAH) effect, in which electrons behave as if they split into fractions of themselves.
Those fractional entities are anyons.
Meet the Anyons: Where “Anything Goes”
Anyons occupy a strange middle ground in the quantum world. Unlike bosons, which happily clump together, or fermions, which avoid one another, anyons follow their own rules—and exist only in two-dimensional systems.
First predicted in the 1980s and named by MIT physicist Frank Wilczek, anyons earned their name as a playful nod to their unconventional behavior: anything goes.
Decades ago, theorists speculated that anyons might be able to superconduct in magnetic environments. But because superconductivity and magnetism were believed to be mutually exclusive, the idea was largely abandoned.
The recent MoTe₂ experiments changed that calculus.
“People knew that magnetism was usually needed to get anyons to superconduct,” Todadri said in a media statement. “But superconductivity and magnetism typically do not occur together. So then they discarded the idea.”
Now, Todadri and MIT graduate student Zhengyan Darius Shi, co-author of the study, revisited the old theory—armed with new experimental clues.
Using quantum field theory, the team modeled how electrons fractionalize in MoTe₂ under FQAH conditions. Their calculations revealed that electrons can split into anyons carrying either one-third or two-thirds of an electron’s charge.
That distinction turned out to be critical.
Anyons are notoriously “frustrated” particles—quantum effects prevent them from moving freely together.
“When you have anyons in the system, what happens is each anyon may try to move, but it’s frustrated by the presence of other anyons,” Todadri explained in a media statement. “This frustration happens even if the anyons are extremely far away from each other.”
But when the system is dominated by two-thirds-charge anyons, the frustration breaks down. Under these conditions, the anyons begin to move collectively—forming a supercurrent without resistance.
“These anyons break out of their frustration and can move without friction,” Todadri said. “The amazing thing is, this is an entirely different mechanism by which a superconductor can form.”
The team also predicts a distinctive experimental signature: swirling supercurrents that spontaneously emerge in random regions of the material—unlike anything seen in conventional superconductors.
Why This Matters Beyond Physics
If experiments confirm superconducting anyons, the implications could extend far beyond fundamental physics.
Because anyons are inherently robust against environmental disturbances, they are considered prime candidates for building stable quantum bits, or qubits—the foundation of future quantum computers.
“These theoretical ideas, if they pan out, could make this dream one tiny step within reach,” Todadri said.
More broadly, the work hints at an entirely new category of matter.
“If our anyon-based explanation is what is happening in MoTe₂, it opens the door to the study of a new kind of quantum matter which may be called ‘anyonic quantum matter,’” Todadri said. “This will be a new chapter in quantum physics.”
For now, the theory awaits experimental confirmation. But one thing is already clear: a rule long thought unbreakable in quantum physics may no longer hold—and the quantum world just became a little stranger, and far more exciting.