The University of Tokyo

RIKEN

Japan Science and Technology Agency (JST)

Announcement Summary

A research group led by Assistant Professor Hironari Isshiki and Professor Yoshichika Otani at the Institute for Solid State Physics (concurrently at the RIKEN Center for Emergent Matter Science), Graduate Student Nico Daniel Budai at the Graduate School of Frontier Sciences, and Associate Professor Tomoya Higo at the Graduate School of Science, the University of Tokyo, has developed a new magnetic imaging technique based on the measurement of local anomalous Nernst effects using an atomic force microscope. Nernst effect using atomic force microscopy. Visualization of the magnetic structure inside a material is extremely important for the study of magnetic materials. However, it is sometimes difficult to obtain magnetic images depending on the target material or element structure. In this study, we developed a method to obtain magnetic images by inducing heat flow on the sample surface with an atomically sharp tip of an atomic force microscope and mapping the voltage signal of anomalous Nernst effect generated in the downward direction orthogonal to the heat flow and magnetization. This simple method has a spatial resolution about ten times higher than conventional methods, and can be widely used to visualize the thermoelectric effect inside a device. In the future, visualization of magnetic domains and thermoelectric effects in antiferromagnetic Weyl semimetals with very small magnetization at high spatial resolution is expected to provide extremely useful information for basic and applied research on next-generation devices.

This result was published in the online edition of the U.S. scientific journal Applied Physics Letters on March 2, 2023 (local time), and was selected as an Editor's Pick, a paper of note.

Figure: Magnetic imaging technique using atomic force microscopy

For more information, please visit the website of the Institute for Solid State Physics, The University of Tokyo.