Hidden Atomic Spiral in Uranium Crystal Reveals Rare Dual Magnetism

Physicists have uncovered a hidden architectural secret inside a crystal that scientists first synthesized more than half a century ago, and the discovery could reshape how researchers hunt for materials to power the next generation of computer memory. A team led by Dr. Mengke Liu, an assistant professor of physics at The University of Texas at Dallas, has identified a previously unrecognized chiral superlattice in uranium oxytelluride, a compound known by its chemical formula UOTe. The finding, published online on October 7 in the journal Nature, explains how a single material can simultaneously exhibit two forms of magnetism that are usually considered opposites, a combination that could prove extraordinarily valuable for advanced electronic and memory technologies.

The story began not with a deliberate search for exotic magnetism but with routine curiosity. While Liu was a Harvard Quantum Initiative Postdoctoral Fellow, before she joined the UT Dallas faculty in 2025, her collaborator Dr. Sheng Ran, an associate professor of physics at Washington University in St. Louis, supplied her with crystals of the uranium compound that he had synthesized in his laboratory. Liu, an experimental physicist with deep expertise in imaging technology, set out to examine the material using two of the most powerful tools in modern condensed matter research: transmission electron microscopy and scanning tunneling microscopy. These techniques allow scientists to generate high-resolution images of a material’s surface and interior structure at the scale of individual atoms, revealing arrangements that no optical microscope could ever resolve.

What emerged from the images was a surprise. Instead of the simple, expected crystal pattern, Liu detected a repeating, twisted structural motif of atoms, a so-called chiral superlattice. The term chiral describes structures that exist in mirror-image forms, twisted predominantly in either a left-handed or a right-handed direction, much like the helices of DNA or the threads of a screw. In UOTe, this spiral organization is not a defect or an impurity but an intrinsic, naturally occurring feature of the crystal, built into the way the atoms stack together over distances far larger than a single unit cell. “I was originally studying this material for an entirely different reason,” Liu said. “When I examined it with high-resolution microscopy, I found a naturally occurring superstructure no one had recognized before.”

The significance of the spiral became clear when the researchers studied how electrons move through the material. In an ordinary crystal, electrons behave according to the symmetry of the underlying atomic lattice, but the chiral superlattice breaks that symmetry in unusual ways. The team determined that electrons traveling through UOTe behaved in unexpected manners because the material possesses both ferromagnetic and antiferromagnetic characteristics at once. Ferromagnets are the familiar magnets of everyday life, in which atomic magnetic moments align in the same direction to produce a net magnetization that can stick a note to a refrigerator. Antiferromagnets, by contrast, arrange their neighboring magnetic moments in opposing directions so that they cancel one another out, yielding a net magnetization of zero even though the material is internally ordered magnetically.

“Finding a single material that combines both of these properties is interesting fundamentally,” Liu said. The coexistence is rare because the two forms of order typically compete: a crystal tends to settle into one magnetic ground state or the other. In UOTe, the chiral superlattice appears to mediate between these tendencies, producing what the researchers describe as a spin-split topological antiferromagnetic state. In such a state, the antiferromagnetic order remains intact, but the electronic structure acquires a splitting associated with spin, a property long sought because it could allow information to be encoded and manipulated using the internal magnetic texture of a material while the material itself appears externally nonmagnetic.

Liu was not alone in her fascination with the compound. At Harvard University, a team led by co-corresponding author Dr. Suyang Xu, the John L. Loeb Associate Professor of the Natural Sciences, was simultaneously investigating the same material from a complementary experimental angle. The two groups regularly shared and compared their findings, and the interplay between the different measurements brought together pieces of the puzzle that neither team could have assembled alone. Through extensive additional measurements, the researchers confirmed that the material’s unique atomic organization is a key factor governing how electrons travel through it, tying the exotic transport behavior directly to the hidden spiral structure rather than to any incidental property of the samples.

The practical implications could be substantial. Magnetic computer memory, which stores bits by orienting magnetic regions within a device, currently relies overwhelmingly on ferromagnetic materials. But ferromagnets have well-known weaknesses: their net magnetization makes them vulnerable to stray external magnetic fields, which can corrupt stored data, and the physics of switching their magnetization imposes speed limits. Antiferromagnetic materials are generally more resistant to perturbation from external fields and can, in principle, operate far faster than conventional ferromagnets, because their dynamics involve much higher characteristic frequencies and their zero net moment shields them from unwanted magnetic interference. “If those advantages can be harnessed, memory devices could potentially become both faster and more robust,” Liu said. A material that combines antiferromagnetic stability with ferromagnetic-like electronic behavior, stabilized by a chiral superlattice, offers a plausible route toward that goal.

The discovery may extend well beyond a single compound. The researchers also carried out computational analyses suggesting that hundreds of related compounds could host similar superlattice structures, hinting at a broad and largely unexplored family of materials with comparable properties. “This study provides a new way of looking for materials with these unusual properties,” Liu said. “Instead of focusing only on the fundamental atomic arrangement, we can also now explore larger superstructures that might influence how electrons behave.” That shift in perspective, from cataloging the periodic arrangement of individual atoms to searching for larger-scale twisted superstructures, could guide materials scientists toward candidates for topological electronics, spintronics and quantum technologies that conventional screening approaches would overlook.

Perhaps the most striking lesson of the work is how much remains hidden in materials that science has long considered settled. Uranium oxytelluride has been known since the 1960s, yet it has been largely ignored in research since then, relegated to the margins of the literature while attention flowed toward newer compounds. “Uranium oxytelluride has been known since the 1960s, but it has been largely ignored in research since then. Now, with today’s techniques, we’re able to uncover and study properties that previously were hidden,” Liu said. Modern imaging tools capable of resolving individual atoms, combined with sensitive probes of electronic and magnetic behavior, are giving researchers a second look at old crystals and revealing features that earlier generations of instruments simply could not see.

The study, titled “A chiral superlattice route to spin-split topological antiferromagnetism,” was an international effort. In addition to Liu, Xu, Ran and co-corresponding authors Dr. Philip Kim of Harvard and Dr. Jianxiang Qiu, now at the University of California, Berkeley, the author list includes researchers from Howard University; Argonne National Laboratory; Los Alamos National Laboratory; Northeastern University; Michigan State University; Texas A&M University; Boston College; the University of Michigan; the National Institute for Materials Science in Japan; the S. N. Bose National Centre for Basic Sciences in India; the Institute of Physics, Academia Sinica in Taiwan; National Cheng Kung University in Taiwan; the Max Planck Institute for Chemical Physics of Solids in Germany; Johannes Gutenberg University Mainz in Germany; and Delft University of Technology in the Netherlands. The research was funded in part by the U.S. Department of Energy, the Office of Naval Research, the National Science Foundation, the Air Force Office of Scientific Research and the Army Research Office. As laboratories around the world begin to search their own crystal collections for hidden spirals, a compound that sat quietly on the shelves for six decades may turn out to be the template for a whole new class of magnetic materials.

Subject of Research: Chiral superlattice structure and dual magnetic properties of uranium oxytelluride

Article Title: Researchers find hidden spiral structure in crystal material

Article References: Researchers find hidden spiral structure in crystal material. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: chiral superlattice, uranium oxytelluride, antiferromagnetism, ferromagnetism, topological materials, transmission electron microscopy, scanning tunneling microscopy, magnetic memory, spintronics, condensed matter physics, Nature journal, quantum materials