Their findings open the door to creating advanced electronic devices that utilize nonmagnetic materials.

For the first time, researchers in Japan have observed a giant anomalous Hall effect (AHE) in a nonmagnetic material. Using high-quality thin films of the Dirac semimetal Cd₃As₂ under an in-plane magnetic field, the team carefully tuned the electronic band structure to isolate the AHE signal. They found that the effect originates from orbital magnetization rather than electron spin, challenging long-standing assumptions in condensed matter physics.

Figure 1. Giant Anomalous Hall Effect in Nonmagnetic Material

Understanding the Hall Effect

In 1879, physicist Edwin Hall discovered that an electrical current flowing through a conductor in a magnetic field produces a voltage across the material. This phenomenon, later named the Hall effect, soon attracted significant scientific interest and became important in both theoretical and applied physics. Shortly thereafter, scientists observed a similar phenomenon in magnetic materials, which came to be known as the anomalous Hall effect (AHE). Figure 1 shows Giant Anomalous Hall Effect in Nonmagnetic Material.

Unlike the standard Hall effect, the anomalous Hall effect (AHE) has long been difficult to explain. For decades, scientists debated its origin, with some proposing that it could occur in nonmagnetic materials—though no experimental evidence had confirmed this. In a recent study, Associate Professor Masaki Uchida and his team at the Institute of Science Tokyo, Japan, reported the first observation of the AHE in a nonmagnetic material. Their findings were published in Physical Review Letters on September 2, 2025.

The Significance of Dirac Semimetals

The researchers achieved this discovery using Dirac semimetals, which feature unique electronic band structures called Dirac points, where electrons behave as if they are massless. Applying an external magnetic field breaks the system’s symmetry, transforming Dirac points into Weyl points and creating more complex, directional electron behavior. By precisely tuning the band structure, the team was able to suppress the ordinary Hall effect and isolate the anomalous Hall effect (AHE) on its own.

“Our study provides the first experimental confirmation that the anomalous Hall effect (AHE) can be quantitatively observed in nonmagnetic materials using in-plane magnetic fields,” Uchida explained.

The team used molecular beam epitaxy to create high-quality thin films of Cd₃As₂, a Dirac semimetal with the required symmetries. They applied an in-plane magnetic field and measured the material’s Hall conductivity. By analyzing how conductivity changed with variations in the magnetic field, the researchers determined the magnitude of the induced anomalous Hall effect (AHE). Remarkably, their setup produced a giant AHE, and further analysis indicated that the effect arose from orbital magnetization—magnetization caused by the orbital motion of electrons rather than their spin.

Potential Applications in Future Devices

Overall, these findings shed new light on a well-studied yet not fully understood physical phenomenon. “Our approach is broadly applicable beyond Dirac semimetals and challenges long-standing assumptions about Hall effects [1]. Future research may enable the development of next-generation devices,” Uchida explained.

Understanding the anomalous Hall effect (AHE) in greater detail also opens the door to exploring electron behavior driven by orbital magnetization. “We anticipate that these results will stimulate both fundamental physics research and applied studies into devices utilizing the AHE,” Uchida added. “Hall sensors and other AHE-based devices in nonmagnetic materials could become more efficient and function under a wider range of conditions than current technologies.”

References:

1. https://scitechdaily.com/rethinking-physics-scientists-discover-a-giant-new-twist-on-a-140-year-old-effect/

Cite this article:

Janani R (2025), Scientists Uncover a “Giant” Twist on a 140-Year-Old Physics Effect, AnaTechMaz, pp. 281