Researchers from the Institute of Science Tokyo have made a groundbreaking discovery: in-plane magnetic fields induce an anomalous Hall effect in EuCd₂Sb₂ films. By studying how these fields alter the material’s electronic structure, the team uncovered a significant in-plane anomalous Hall effect. This finding opens new avenues for controlling electronic transport in magnetic fields, with exciting potential applications in magnetic sensors.

The Hall effect, a well-known phenomenon in materials science, occurs when an electric current in a material is subjected to a magnetic field, creating a voltage that is perpendicular to both the current and the field. While much research has been conducted on the Hall effect under out-of-plane magnetic fields, the effects of in-plane magnetic fields have been less explored. Recently, however, in-plane magnetic fields have garnered increasing attention due to their potential to unlock new material behaviors, particularly in materials with unique electronic band structures, like EuCd₂Sb₂.

This recent study, conducted by researchers at the Institute of Science Tokyo and the RIKEN Center for Emergent Matter Science (CEMS), led by Associate Professor Masaki Uchida, explores how in-plane magnetic fields induce the anomalous Hall effect in EuCd₂Sb₂ films. Published in Physical Review Letters on December 3, 2024, the study sheds new light on how these magnetic fields induce significant changes in the material’s electronic band structure.

Uchida and his team have uncovered that in-plane magnetic fields induce a notably large anomalous Hall effect in EuCd₂Sb₂ thin films. This effect is highly sensitive to the direction of the applied magnetic field, as the Hall effect’s sign changes with the rotation of the in-plane magnetic field. The researchers observed a clear three-fold symmetry in the effect, indicating a strong directional dependence.

The study further revealed that the anomalous Hall effect is connected to an unusual out-of-plane shift in the singular points of the material’s electronic band structures. This shift is linked to orbital magnetization—the rotational motion of electron wave packets—which plays a crucial role in the material’s magnetic properties. The researchers’ findings enhance our understanding of how in-plane magnetic fields influence the internal structure of advanced materials.

In addition to the intriguing theoretical insights, the researchers found that small adjustments in the angle of the magnetic field can lead to significant variations in the in-plane anomalous Hall effect. This directional sensitivity suggests that materials like EuCd₂Sb₂ could be highly effective in technologies requiring precise measurement of magnetic fields along specific directions, such as magnetic sensors.

“This work not only represents a breakthrough in experimentally studying orbital magnetization but also encourages further materials development for future applications,” said Uchida. “It transforms the concept of the Hall effect from the traditional out-of-plane configuration to an in-plane approach, offering new opportunities for future technologies.”

The findings from this study offer valuable insights into how in-plane magnetic fields can modify the electronic properties of advanced materials like EuCd₂Sb₂. The work is expected to inspire future developments in materials with tailored magnetotransport properties, opening the door to the creation of more efficient and precise magnetic sensors and other technologies that depend on controlling electronic transport in magnetic fields.

By advancing our understanding of how in-plane magnetic fields influence material behaviors, this study brings us one step closer to unlocking the full potential of magnetic materials in next-generation technologies.

By Impact Lab