Illuminating Quantum Antiferromagnets with Light: Scientists Visualize Magnetic Domains

Illuminating Quantum Antiferromagnets with Light: Scientists Visualize Magnetic Domains
by Riko Seibo
Tokyo, Japan (SPX) Oct 13, 2024

Researchers from Osaka Metropolitan University and the University of Tokyo have made a significant advancement in the study of quantum materials. Using light, the team successfully visualized magnetic domains - small regions where atomic spins align in the same direction - within a specialized quantum antiferromagnetic material. These magnetic domains were manipulated using an electric field, providing new insights into the behavior of quantum magnets.

While most are familiar with traditional magnets, antiferromagnets have emerged as a key focus for future technology development. These materials differ from typical magnets, as their magnetic forces cancel each other out, making them non-magnetic on the surface. Despite this, antiferromagnets with quasi-one-dimensional quantum properties hold promise for next-generation electronics and memory devices.

"Observing magnetic domains in quasi-one-dimensional quantum antiferromagnetic materials has been difficult due to their low magnetic transition temperatures and small magnetic moments," explained Kenta Kimura, an associate professor at Osaka Metropolitan University and the study's lead author.

The research team focused on the quantum material BaCu2Si2O7, using a method called nonreciprocal directional dichroism to observe the material's magnetic domains. This method allowed them to visualize opposite domains coexisting within a single crystal, with domain walls aligned along specific atomic chains.

"Seeing is believing and understanding starts with direct observation," Kimura commented. The team's approach, using optical microscopy, also demonstrated that these domain walls could be moved using an electric field through magnetoelectric coupling, while maintaining their original direction.

"This optical microscopy method is straightforward and fast, potentially allowing real-time visualization of moving domain walls in the future," added Kimura.

This discovery represents a major leap in understanding and manipulating quantum materials, with potential applications in future quantum devices. "Applying this observation method to various quasi-one-dimensional quantum antiferromagnets could provide new insights into how quantum fluctuations affect the formation and movement of magnetic domains, aiding in the design of next-generation electronics using antiferromagnetic materials," said Kimura.

Research Report:Imaging and control of magnetic domains in a quasi-one-dimensional quantum antiferromagnet BaCu2Si2O7