CMU Physicists Discover New Form of the Hall Effect
Carnegie Mellon University researchers discovered an unconventional anomalous Hall effect that occurs when magnetization lies within the plane of a material. The multidirectional response emerges from a low-dimensional heterostructure combining a low-symmetry topological semimetal with a ferromagnetic insulator.
Experimental and theoretical analysis links the effect to reduced symmetry, interfacial spin-orbit coupling, and exchange interactions. Published in Nature Materials, the findings may support tunable Hall effects and future applications in magnetic sensing and quantum materials.
Researchers at Carnegie Mellon University have uncovered a new phenomenon that expands the fundamental understanding of the Hall effect, a principle widely used to study the magnetic and electronic properties of materials.
The Hall effect describes a measurable electrical response that occurs when moving charges in a material interact with a magnetic field. It has long been an important tool for studying how electronic materials behave.
In the new study, CMU physicists demonstrated an unconventional form of the anomalous Hall effect in which the response can occur with magnetization oriented within the plane of the material. The finding challenges the conventional symmetry assumptions associated with the Hall response.
The researchers created a low-dimensional heterostructure by combining a low-symmetry topological semimetal with a ferromagnetic insulator. The resulting structure has reduced symmetry, which enables the multidirectional anomalous Hall response observed by the team.
According to the researchers, the interaction between the magnetic and nonmagnetic layers plays an important role in producing the unusual response. Their theoretical model helps explain how interfacial spin-orbit coupling and exchange interactions contribute to the effect.
The researchers say the discovery provides a pathway for engineering tunable, symmetry-driven Hall effects in low-dimensional quantum materials. It could also contribute to the development of new approaches for magnetic sensing and other technologies that depend on controlling or measuring magnetic properties.
The study combines experimental observations with theoretical analysis to explain the origin of the multidirectional response. The work demonstrates how carefully engineered material interfaces can produce electronic behavior that is not found in conventional systems.
The research was published in Nature Materials and involved researchers from Carnegie Mellon University and collaborating institutions. The findings add to the growing body of research into low-dimensional quantum materials and new ways of controlling their electronic and magnetic properties.
