Can magnons travel across domain walls?

In April 2023, Prof. Tianxiang Nan (Tsinghua University) and collaborators presented experimental findings that challenge standard modelsof the interactions between magnons and magnetic domain walls. Contrary to expectations, the researchers found that magnons barely feel the presence of 180-degree domain walls in a ferrimagnetic insulator thin film when no external magnetic field is applied.

Nan and his collaborators had to interpret the surprising results obtained with their non-local spin transport measurement. Therefore, they carefully studied the magnetization distribution of their sample when no external magnetic fields were applied and stripe-like magnetic domains would appear.

Quantum Sensing and AI helped answer the question

They performed scanning NV magnetometry measurements using ProteusQ and then inferred the underlying magnetization using this data by applying an AI-based approach developed by researchers from the Quantum Sensing Lab (University of Basel) and Qnami. The information related to the magnetization helped the collaboration to confirm that the magnons do indeed “cross 180-deg domain walls” without loosing their polarization.

These groundbreaking results call for novel ingredients to model the magnon spin diffusion through complex magnetic textures. This is crucial to use magnons for next-generation spintronics devices.

We congratulate Tianxiang Nan and all his collaborators from Cornell University, Stanford University, Tsinghua University, the University of Wisconsin-Madison, and the University of Basel, for this exellent results.

To dive deeper into this research, head over to our dedicated application page. If you prefer, directly access the full article in Nature Communications.

Will your application be the next one?

Prof. Tianxiang Nan (Tsinghua University) shared with us his thoughts on the central role that Scanning NV Magnetometry, thanks to its accuracy, had in this work.

In our work, we probed the magnetic domain structures of an ultra-thin ferrite which are essential to understand how magnons can propagate through magnetic domain walls in magnetic materials. Imaging complex magnetic textures in ultra-thin films is very challenging if not impossible with state-of-the-art techniques. The Qnami ProteusQ made it possible. Hai Zhong and the entire Qnami team provided us with technical support and scientific inputs. We are grateful for such a fruitful collaboration.

Prof. Tianxiang Nan – Tsinghua University

Will your application be the next one?

Nanoscale spin textures in bismuth ferrite measured with Qnami ProteusQ

Scanning NV Magnetometry is unlocking more and more applications in the field of nanoscale magnetism. Can yours be the next one? Let’s find out together. Drop an email to our Application Scientist Dr. Peter Rickhaus (


We would be happy to talk with you, and learn more about the challenges you face when it comes to measuring magnetic properties of your sample. Are you interested in discussing with us about your application? Let’s have a chat.

Qnami ProteusQ

Qnami ProteusQ - thq quantum microscope to probe magnetic properties of your materials at the nanoscale
Qnami ProteusQ

ProteusQ is a complete quantum microscope system. It is the first scanning NV (nitrogen-vacancy) microscope for the analysis of magnetic materials at the nanoscale. The system allows user to detect extremely small magnetic fields generated from a wide range of materials, even antiferromagnets.  

Are you interested in exploring how ProteusQ can help you prove your hypotheses and push the frontiers of science? If you are curious, then contact our Sales Managers, Dr. Joerg Lenz and Benjamin Holmes (

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